Contemporary Music Review Vol. 24, No. 1, February 2005, pp. 39 – 51
Abnormal Playing Techniques in the String Quartets of Helmut Lachenmann David Alberman
This article is an attempt to classify and describe the array of new techniques that Helmut Lachenmann has invented or exploited for string instruments. I mention features of each extended technique and give examples of where they occur in the three string quartets. I have also created a chart to help readers identify these new sounds. Keywords: Extended Techniques; Listening; String Quartet 1 Introduction A defining feature of Lachenmann’s music is a subversion of inherited musical norms through which he comes to terms with his musical genes. Clear examples of this are to be found in his writing for string instruments in his three string quartets: Gran Torso (1971/1972, with later revisions), Reigen seliger Geister (1989), and Grido (2000/ 2001, revised 2002). In this essay I shall define the broad features of the norms of playing technique that Lachenmann confronts (section 1.2) and describe the abnormal techniques as seen in the quartets, which arise from this encounter (section 2). I will also suggest a loose taxonomy of sounds and techniques, which point to their compositional significance (Figure 2, discussed in section 3). In conclusion, I shall discuss the significance of these sounds and techniques to interpreter, audience and composer (section 4). Where I refer to Lachenmann’s own words, they are taken from Musik als existentielle Erfahrung (MaeE; Lachenmann, 1996). All translations and errors pertaining thereto are my own. 1.1 Notation I will not spend much time discussing or explaining Lachenmann’s notation. His publisher has to some extent provided a key to musical symbols, but not always to ISSN 0749-4467 (print)/ISSN 1477-2256 (online) ª 2005 Taylor & Francis Ltd DOI: 10.1080/0749446042000293592
40
D. Alberman
instructions in German next to the stave. Should any reader prefer to contact me rather than the composer for clarification, I will be delighted to help if I can. In this article, however, I want to describe not only how Lachenmann’s new sounds are produced and how they strike the ear, but also, more importantly, I would like to discuss the significance to Lachenmann and to us of these sounds and techniques. The use of visual symbols to capture the music is for me to some extent a distraction from this discussion. What then does one lose if one discusses new sounds and techniques without discussing notation? The answer for me depends on the composer. Without going into Barthesian or Schoenbergian discussions about the relationship between text as seen, text as heard and text as neither seen nor heard, I believe that some composers conceive their music in textual/symbolic form more than others. Iannis Xenakis, for instance, conceived of structures that he discovered and invented in symbolic form. He could not illustrate them on an instrument and did not discover them by experimentation on an instrument, although he had a very clear concept of how his works should sound (string players, for example, should never use vibrato unless specifically requested to do so). The irrelevance of metre in much of Xenakis’ music and the probabilistic distribution of events in time suggest to me that the notation is an antecedent of the music as it sounds in a way quite unlike the case with Lachenmann. Lachenmann set out to discover new sounds and techniques for producing them on string instruments. Then he adapted classical notation so that the players know what to do. In that sense, I believe, the music is self-standing to a larger extent than that of Xenakis by the time it is written down. However, one important insight into the conceptual history of Lachenmann’s techniques is the division and dismantling of the component parts of each technique. By that I mean that established and normal classical techniques consist of particular combinations of left-hand and right-hand activity. For instance: a classical dolce, legato sound is made up of vibrato (i.e. left-hand technique) and bow speed, bow inclination and the contact point of the bow on the string between the bridge and the fingerboard (i.e. righthand technique). Lachenmann has separated out these elements (whether ‘deconstructed’ is the proper word is a question for another discussion) and uses different staves for left-hand and right-hand activity, which allows him, for instance, to specify that the hands should be rhythmically independent (Reigen, m. 109, violin 1). Lachenmann’s notation also allows him to make clear where he takes a sound which would be continuous in classical music, but which he has dissolved into its molecular parts. I shall limit myself to one example of notation, and discuss these and other issues, in section 2.9. 1.2 The Norms of String Technique For the average listener, the expected sound of string instruments in classical (as opposed to popular) music, whether of the present or the past, is clearly and rather narrowly defined. While the exploration of period practices has made the sound of
Contemporary Music Review 41 string instruments played without vibrato or slides much more familiar than was the case perhaps 30 years ago, certain preconceptions still apply: 1. 2. 3. 4. 5. 6. 7.
String instruments produce pitched sounds. String instruments were not designed to produce unpitched sounds. Where pitch is defined by the composer, it can invariably be expressed as a frequency of string vibration related to the pitch of the open strings. The pitch of each string is altered by stopping it with the fingers. The sounds are produced by drawing the hair of the bow across the strings, or by plucking the string with the fingers. The physical process of producing sounds in these ways implies an initial attack followed by a decay of various lengths and gradients. Performers aim to project their playing so that all pitched sounds, however soft, are easily identifiable. Vibrato is frequently used to help project these sounds and thicken their texture.
2 How Does Lachenmann Confront These Norms? 2.1 Pitched Sounds Pitched sounds are present in all of the string quartets—the open strings (whether detuned or not) and their harmonic spectra underpin the harmonic structures. Lachenmann uses the left hand to stop quarter-tones, further expanding his palette. But the role of pitched sound in the quarter-tones cannot be seen in context without considering their relationship to unpitched sounds. While all of the string quartets have a highly wrought harmonic structure (where they have a harmonic structure), the pitch structure is frequently not heard in the foreground, but rather as a nuance of unpitched timbral effects. This is the exact opposite of classical practice, where the timbre is usually a nuance or pigment of the pitch. I suggested above that purely unpitched sounds are never specified in classical string music; I have found no example before the 1950s. Lachenmann has developed an elaborate language of unpitched sounds for string instruments. He speaks of undertaking ‘botanical expeditions’ to discover new sounds, and techniques for producing them. His own lack of a formal training in string technique meant that he was not limited by, say, a normal bow hold when using the bow to produce sounds. In fact he developed a technique, Faustgriff (fist grip), for controlling the bow when it moves along these new trajectories. It is clear from the interrelation of the different families of sounds which Lachenmann discovered (or invented—a full discussion of the philosophical distinction between the two lies far beyond the scope of this essay), that he was not trying to confront or subvert his heritage as a composer by some sort of grotesque distortion of an idealised beauty in classical music. For one thing, as he himself has written, beauty had become not idealised but stylised, and narrowly at that. It was the
42
D. Alberman
confines and very existence of this conformist model to which he was reacting. In response, he developed a formal language in sound, no less rigorous or flexible than the principles of diatonic harmony, which the European tradition had bequeathed him. His language may contain chords, clusters, contrasts and counterpoint, but they are frequently constructed from sounds related only by timbre, colour, intensity and duration. 2.2 Light Pressure Unpitched Bowed Sounds The hairs of the bow are used to produce sustained sounds, as in classical music; but Lachenmann exploits the unpitched, white-noise-like elements of bowed sounds to produce a colour palette of timbres. In classical playing, much attention is given to choosing the point between bridge and fingerboard where the bow is to be drawn (the ‘contact point’), the downward pressure on the bow exerted by the right-hand fingers and the speed at which the bow is drawn. By using a light bow drawn relatively fast over the fingerboard (flautato), one can avoid producing a pitched sound. A classical player would say that the string was failing ‘to speak properly’. Lachenmann would say, I suspect, that the string in his music is speaking, but in a different language. This is often guaranteed by Lachenmann by using the fingers of the left hand to dampen the open strings and thus limit their vibration. What emerges is a sound akin to soft breathing. The timbre of breathing sounds can be altered by changing the shape of the mouth. The effect desired by Lachenmann is analogous to this. Because (hitherto, at least) it is impossible to specify timbral colours as precisely as pitch, Lachenmann instead specifies the contact point, or place on the instrument, where the bow is to be drawn. This tends to produce, fairly reliably, timbres that are darker (e.g. when bowed over the fingerboard) or lighter (e.g. nearer to the bridge). When the strings are being bowed, this variation in timbral darkness (or lightness) is entirely predictable from classical technique—longer lengths of string (as when playing sul tasto) vibrate at a lower frequency than shorter lengths of string (as when playing sul ponticello). Although the use of the bowstick is discussed below, this is the point to note that a subclass of these unpitched light pressure sounds consists of those produced exactly as described in the paragraph above, but using the stick rather than the hair of the bow. The situation is less clear when parts of the instrument other than the strings are bowed. It seems that the mass of wood being made to vibrate determines the colour of the timbre. Although all parts of string instruments are physically interconnected, some parts are better at transmitting vibrations than others. Hence bowing directly on the bridge often produces a dark timbre, because the bridge is, by design, very good at transmitting vibrations to the rest of the instrument. The tuning pegs, by contrast, produce a light sound. Although tuning pegs are identical, it is rare for all four pegs to produce identical timbres when bowed; though bad transmitters of vibration, they do transmit enough for differing proximate masses of wood to produce different timbres. The mute (old-fashioned wooden three-pronged) is an
Contemporary Music Review 43 excellent transmitter of sound; when bowed, it acts as an extension of the bridge and tends to darken the sound, as well as making it more reverberant. Grido in particular makes use of this effect. A final point is that the stick of the bow itself is a vibrating mass of wood and also a good transmitter of vibration. Therefore, as the bow is drawn, different timbres can emerge simply because of the point along the length of the bow that is being played. 2.3 Light Pressure Partly Pitched Bowed Sounds By touching the string lightly with the fingers of the left hand, the string can be made to vibrate indistinctly at a given pitch. When combined with the flautato bowing technique as described above, a sound can be produced which to the ear is predominantly unpitched, but which has the flavour, or perhaps the memory, of a pitch. Lachenmann describes these sounds as spha¨risch meaning ‘of the spheres’. I would argue that these sounds in particular represent a subversion of the classical norm: pitch is not absent and is a part of a perfectly coherent harmonic scheme—but it is subordinate to timbral colour in the musical narrative. 2.4 Heavy Pressure Pitched Bowed Sounds The bow produces sound because its hair has a series of microscopic notches that catch the string and make it move. In classical music, these notches pull the string so as to produce a continuous vibration of the string. An apparently continuous sound is heard. However, by reducing the bow speed and holding the bow in the fist of the right hand (Lachenmann’s ‘fist grip’) to focus and control downward pressure, a discontinuous sound will emerge. The string can be made to vibrate in a series of single, discrete movements. A single movement will sound like a click. Lachenmann himself compares this sound to the click made by a car engine as it cools after having been switched off. A series of these movements will sound like a Lilliputian snoring of great purity and charm, although it is made up of single clicks. This snoring will have a timbral pitch—or lightness or darkness, as above, depending on bow speed, contact point and position along the length of the bow. But another layer of pitched sound is heard because the increased pressure of the bow on the string is enough to stop the vibrating length of the string, exactly as the fingers of the left hand do in classical technique. In this way, two pitches, sometimes moving in contrary motion (depending on whether the bow contact point is shifting), can be heard. The resultant pitches and their colour and clarity will furthermore depend on whether this bowing technique is being used over an open string, or a string that is being lightly dampened at an indeterminate pitch, or stopped at a predetermined point. It is worth noting that Lachenmann has a perfectly understandable horror of the otherwise comically birdlike sounds that can accidentally arise from using too much bow pressure when bowing a part of
44
D. Alberman
an instrument other than the strings (e.g. pegs, scroll, tailpiece). It is no doubt in part to prevent these accidents that many of the more fragile playing techniques in Lachenmann’s music bear dynamic markings in quotation marks. Thus ‘ff’, as opposed to ff, indicates to the performer that the absolute dynamic in decibels of a passage can never be very loud and that it would destroy the effect to try to produce a loud sound, but that the loudest secure version of this sound should be played and that it is a prominent voice in the music at that point. In this category also belongs Lachenmann’s instruction to end a note by stopping the bow dead on the string and not lifting it away, so that the note may ring on. This neatly subverts the almost unconscious convention of classical technique that the tapering of the end of a note should be as carefully controlled as the initial attack of the note. 2.5 Heavy Pressure Unpitched Bowed Sounds It is arguable whether this category is represented. As pointed out in the previous paragraph, increased bow pressure on the string acts to stop the string at a coherent pitch. Therefore if the string moves at all, even for a single click, it is difficult for no perception of pitch to take place. 2.6 Normal Pressure Bowed Sounds Sounds belonging to this category subvert various norms. Perhaps the most arresting sound is the ‘backward tape’ or ‘yapping’ sound (yapsend in German). This inverts the process of sharply decelerating the bow after the initial attack to produce a sharply delineated decay. The same process is at work in normal speech, so that the tape of a speech played backward is remarkable for its groups of vowel sounds cut off by a reversed ictus, hence ‘backward tape’. In this effect, the bow accelerates sharply from a low speed to set the string ringing (often on a harmonic) only for the left hand abruptly to dampen the sound completely, producing the opposite of an ictus, as the frequency and amplitude of the string’s vibration decrease almost instantaneously. This is also the place to mention the use of scordatura, or detuning of the strings. It is clear from Lachenmann’s own writings (see Lachenmann, 1996, passim) that the strong, familiar aural flavour of string instruments tuned in fifths was an element that could not be left untouched in his enterprise of subverting the safe, bourgeois, iconic legacy of classical music (or ‘serious’ music; ernste Musik, as the Germans say). In fact, in Reigen, in a passage where the strings are suddenly to be detuned in a random way, Lachenmann specifically asks that intervals of a fifth be avoided (m. 317). Beyond the cultural meaning of composing for detuned strings, there are other obvious advantages: the expected timbres of open strings on string instruments are suddenly called into question. Also, techniques that work best, or only on open strings (e.g. pizzicato fluido,
Contemporary Music Review 45 yapping, pizzicati left to ring on), can by means of scordatura be integrated into the intervallic and harmonic structure of the music. Where these open-string sounds are prominent, vibrato, as with many other sounds discussed in this article, is made redundant. 2.7 Unbowed Sounds Produced with the Bow In making this category I use the word ‘bowed’ to mean that a bowed sound is that produced by drawing the hairs of the bow across a part of the instrument along the long axis of the bow. Lachenmann has found other ways to use the bow to produce sound. To begin with, a number of unpitched sounds are produced by drawing the bow not across the strings, but vertically along the length of the strings. This means that whereas the bow previously could travel up and down, it now also travels down the string and up the string; by combining two directions at right angles, Lachenmann can get the bow hair to circle over the string, producing a continuous change in timbre. Lachenmann’s expeditions through perpendicular universes also yielded a technique of using the bow hair to produce sound without moving the bow linearly at all. By rolling the bow hair against the back of an instrument, a crunching sound is produced, not unlike the sound of splintering or breaking wood. This in itself is a not unsubversive sound to present to a classical music audience. I said above that the vibrating mass of the bow stick and hair could determine the pitch, or timbral pitch of a sound. This phenomenon is heavily exploited by Lachenmann in Gran Torso. Bouncing the hairs of the bow on the face of the bridge produces a clearly pitched sound. By drawing the bow at the same time as bouncing it, the pitch changes, according to the length of hair and bow stick, which is permitted to vibrate. There is also a passage where the cellist holds the stick of the bow with two hands, whose distance from each other is specified in centimetres. At the same time, the bow is drawn vertically up and down the string. Once again, the length of vibrating masses of hair and bow stick determine timbral pitch. A colourful example of Lachenmann’s attention to detail occurs in this same passage: both of the cellist’s hands are occupied with the bow, but Lachenmann needs to dampen the strings in order to achieve the desired effect. The solution to the problem is for the cellist to stop the strings with his or her chin. The place of pride in this category must go to the effect in Gran Torso whereby the thumb of the left hand moves swiftly along the bow hair to produce a pitchless timbre. The instrument is used as a resonating cavity, but the sound is produced entirely with the bow. An important subcategory of these sounds contains those produced only with the bow stick. The Second Viennese School had, long before Lachenmann, produced sounds by bowing only on the bow stick, without any hair. Hector Berlioz, in the Symphonie Fantastique, famously uses the bow stick to strike the string, again without the use of the hair. But Lachenmann was the first composer to use the bow stick both to strike the string and simultaneously to determine the resultant pitch of the sound
46
D. Alberman
produced. This happens because the left hand is used only to dampen the open strings; the point at which the bow stick hits the string, as with over-pressured bow hair, is the point that determines the vibrating length of the string and thus the resultant pitch. The bow stick is also used as percussion instrument where it is forced to bounce on a string that has been made to vibrate by a left-hand pizzicato. 2.8 The Fingers Lachenmann’s abnormal techniques extend to the fingers of both hands. Left-hand pizzicato is a familiar feature of classical technique. Sometimes one left-hand finger plucks a note that is being stopped by a different left-hand finger. But Lachenmann’s use of what he calls pizzicato fluido is unique. In this technique, an open string is plucked by a left-hand finger. Almost immediately afterwards, the bow hair tension screw (and occasionally the bow stick) is placed lightly on the still vibrating string to produce a stopped pitch that will ring on long enough to be changed either by a glissando or a vibrato with the tension screw/bow stick. The sound is not unlike a Hawaiian guitar, or a pedal steel guitar. Thus the role of the hands has been not so much subverted as inverted in respect of classical technique: the left hand supplies the impulse and the right hand stops the string; the pizzicato, moreover, has turned from a short note of fixed pitch to a legato sustained sound of variable pitch. The use of light left-hand pressure has already been mentioned. Lachenmann frequently uses intermediate left-hand pressures, which lie between those of classical technique, where the left-hand fingers either depress the strings firmly enough to produce a stopped pitch, or lightly enough to produce a harmonic. Care must be taken to maintain an even pressure wherever the stopping point may be on the string. In extremely high positions (11th position and above), it is sometimes necessary to depress the strings either side of the played string in order to prevent three strings sounding at once. Lachenmann also uses the fingernails of both hands: when plucking the edge of the bridge, for instance, in order to create several versions of the same sound. Lachenmann also uses the left-hand fingers to produce a sound not by pressing the string, but by releasing it (rosin on strings, and general stickiness, causes the strings to start ringing—Lachenmann exploits this usually problematic phenomenon in a manner analogous to his use of the sound caused by a sudden stop in bow travel as opposed to the carefully graduated deceleration of classical bowing technique). 2.9 Notation—an Example In order to preserve the character of Lachenmann’s handwritten playing material, I have cropped the image in Figure 1 rather loosely. The bottom two staves beneath the time signature are the second violin part. The upper of these two staves indicates the bowing technique. The lower stave shows the resultant pitch (shown as approx[imate] but not indeterminate) and the left-hand technique. On the upper
Contemporary Music Review 47
Figure 1 Second Violin Part, from Lachenmann’s Second String Quartet, ‘Reigen seliger Geister’, p. 62, mm. 369 – 370. # 1989, Breitkopf & Ha¨rtel, Wiesbaden.
stave, the full instruction to the left of the line in the original is ‘arco gepresst, Bogen in Faust, Zeigefinger auf Bogenstangenru¨cken gelegt’ (‘press the bow, bow in fist, index finger placed on the back of the bow stick’). The crenellated descending line is a representation of the closely spaced, almost continuous clicks that are produced. The descent of this line through the upper stave shows that the contact point of the bow should shift gradually from somewhere near the bridge to somewhere over the fingerboard. It is this shift in contact point which changes the vibrating length of the strings (which have been specified two bars earlier as the detuned third and fourth, D and G, strings) and hence the resultant pitch as shown in the lower stave. See section 2.4 for an explanation of this effect. Note the marking mp express[iv]. Here is a keyhole glance at Lachenmann’s view of his own music. The origin of these playing techniques may have been a highly organised programme of subversion, but the music that Lachenmann produces using these techniques is often warm, gentle and expressive. Interpreters forget this at their, and the music’s, peril. The syncopated ‘notes’ beneath the lower stave are in fact instructions to dampen and undampen the strings in the given rhythm. The notehead O signifies an undampened open string. The notehead Ø signifies that the open string should be dampened lightly with the left hand. See again section 2.4 above for an explanation of this effect. In general, it is the precisely specific nature of the notation that is most relevant to the theme of this article. Even the word ‘approx.’ in this example is subject to a footnote in the original (‘the given pitches show what ought to result from the shifting of the pressed bowing action’). Lachenmann has specified how to play, separating each hand; then he has explained what the result should be, although this
48
D. Alberman
is contingent on the correct technique being used (and not vice versa). Before all of this, he indicates the dynamic and expressive character of the music. Thus, the notation illustrates the composer’s order of priorities in creating his music and the position of playing techniques within that order. 3 A Taxonomy of Sounds (Figure 2) In Figure 2, abbreviations of the references GT, RE and GR refer respectively to Gran Torso, Reigen seliger Geister and Grido; bar numbers follow work titles; V1, V2, VA and VC refer respectively to violin 1, violin 2, viola and cello. The taxonomy in Figure 2 is not original, but a schematic representation of Lachenmann’s own groupings and categories in MaeE passim. It is clear from Lachenmann’s own accounts that the transitions and metamorphosing of musical material from one category in Figure 2 to another are a fundamental engine of narrative progress. For that reason, I have categorised the playing techniques in a way that does not neatly match the groupings of the previous discussion. My reason for doing this was that my interpreter’s view of the playing techniques themselves and Lachenmann’s view of them as a composer are two separate subjects; I wished, however, to nod to both subjects even if I did not discuss both of them in equal detail. The taxonomy does not pretend to be an exhaustive account of all of the playing techniques that could be considered abnormal. I have concentrated on those which I felt needed most explanation.
4 Conclusions 4.1 The Significance of the Playing Techniques for Interpreters While learning these techniques, I would argue that they need to have no significance at all. What is paramount is a patient mastery of the sounds. That a classical son file´ is being subverted by a spha¨risch long note is irrelevant if the player allows a clear pitch to contaminate and poison the sound even for a nanosecond. Obedience is more important than faith. These techniques use the instruments in ways unimagined by their makers. If performed carefully, they will not damage an instrument. However, they clearly challenge the player to accept the sounds produced into the canon of classical concert music sounds. The structure of Lachenmann’s music grows from the nature of the techniques themselves: rubbed sounds, for instance, may transform from one instrument to another into short, impulse sounds. This transition may be a vital link between two sections of a piece and so great precision is vital in obeying the composer’s instructions. The techniques, in short, are not optional when playing the music—they are the music. One could not, for instance, transcribe Lachenmann’s three string quartets for piano four hands; the music would simply disappear.
Contemporary Music Review 49
Figure 2 A Taxonomy of Some Playing Techniques in Lachenmann’s String Quartets.
50
D. Alberman
Following on from this, a large portion of the interpretative task—the selection of sounds and techniques appropriate to the music—simply falls away. This is not an emasculation of the interpreter—his or her role merely becomes subtler. This article shows how tight the circumscription of the technical possibilities is for the interpreter. But, to take an example, the elements of irony, nostalgia and provocation conjured up by classical rhythmic patterns in the string quartets (waltz, march, siciliano, etc.) can be mixed afresh for every performance while respecting the technical instructions. Interpretation has been purified, not legislated away. 4.2 The Significance of the Playing Techniques for Listeners If well executed, these techniques will produce sounds that are occasionally hard to hear (Lachenmann permits amplification if the acoustic is too unworkable, and the third quartet, Grido, was supposedly written so as to be more easily audible than the first two quartets) and occasionally hard to listen to if the listener has a rigid requirement (a) for beauty as they conceive it at all times and (b) for that beauty only as defined by, say, Herbert von Karajan. That is precisely the idea. Perhaps central to this is that by use of indeterminate scordatura, quarter-tones and purely timbral sounds, diatonic pitch has lost its primacy in the substantive composition of musical sound. This raises for me the question of whether the subversive and challenging effects of these playing techniques fully operates only on first hearing. Does the aesthetic process involved collapse on repeated hearings? Are these sounds anything more than an act of rebellion? Beethoven can help here. The Eroica symphony is not necessarily revolutionary to 21st-century ears; but it makes little sense to say that the music therefore fails in its aesthetic project. An understanding of the distance between the Eroica and the status quo ante may deepen the listener’s appreciation; but the piece speaks ultimately to the relationship between the composer’s more than the listener’s past and present. The ready accessibility today of music from the past means that different eras have become concatenated into a timeless cultural landscape. 4.3 The Significance of the Playing Techniques for Composers As a non-composer, I can only offer thoughts from the perspective of an interpreter. The clarity and detail of Lachenmann’s conception of sound derive from his exhaustive research into playing techniques. His notation is often a representation first of what to do and only then of what the most likely resultant sounds are. As such, he lays a heavier burden of responsibility on his own compositional methods than he does on the interpreter’s ability to realise the textual version of the sound, for which I, for one, am grateful; the audible whole of the music is far greater than the sum of the string-technical parts. Lachenmann
Contemporary Music Review 51 (1996, p. 386; in a note on Gran Torso) deserves the last word: ‘These alienated playing techniques mark only the tip of an iceberg of profound contradictions up out of whose depths the bourgeois artist has the opportunity to pull himself by his own bootstraps.’ Reference Lachenmann, H. (1996). Musik als existentielle Erfahrung. Schriften 1966 – 1995 (J. Ha¨usler, Ed.). Wiesbaden: Breitkopf & Ha¨rtel.