Generally speaking, after Brahms's Fourth Symphony the alto trombone seems to have disappeared rapidly from view. It would still see service in the Church in the Posaunenchor or as a Kirchenchorzugposaune, but as far as the symphony orchestra was concerned, by 1914 Cecil Forsyth would declare the alto trombone 'obsolete', placing it in the same category as the serpent, tenoroon and Zink.4 in 1905 and 1907 respectively. Around the same time, Mahler had suggested the alto trombone be used in passages of his Sixth and Seventh Symphonies, and in 1911 Bartók employed no fewer than four altos in the stage band for his opera Bluebeard's Castle6 also called for an alto trombone in his Fünf Orchesterlieder nach Ansichtskartentexten von Peter Altenberg (completed in 1912) in the original 1914 version of Drei Orchesterstücke (Ex. C.1, C.3) and in his 1925 opera Wozzeck (Ex. C.5).
The manner in which these composers employed the alto, however, was a clear departure from the way it had been used in the past. Berg, for example, used the instrument not so much for its tone colour but, taking up where Berlioz left off, as a means of extending the trombone section's upper range. The statement by the former Universal Edition editor H. E. Apostel that appears in the score of the 1929 version of Drei Orchesterstücke (Ex. C.2, C.4), reveals that for Berg the alto was merely one of two options in this regard:
Die 1. Posaune war ursprünglich im Alt-Schlüssel notiert. Aus technischen Gründen und mit Einverständnis des Autors wurde die 1. Posaunenstimme nachträglich in den Tenorschlüssel transponiert. Die mitunter exorbitante Höhenlage erfordert daher die Hinzuziehung einer Alt-Posaune oder einer Trompete in tief Es.7
Moreover, in Berg's Wozzeck (Ex. C.5), although the autograph9 specify that the first trombone is to be played on an alto, most of the part is better suited to the tenor; indeed the composer has written some notes that are too low to be played on the alto.10 Nonetheless, this appears to be the last time in the standard orchestral repertoire that the alto instrument is specifically indicated. Oddly, there is no indication on the trombone part itself ('1. Posaune') that an alto is required.
Lulu, composed more than a decade later, includes similar upper-range parts for the first trombone, yet significantly the autograph does not specify an alto trombone.11 Notwithstanding this, the instrument is frequently used by modern performers in at least the two passages shown in Ex. C.6.
As in Wozzeck, Berg combines both extremities of the trombone range within the same passage, thus technically precluding the use of the alto.14 (see Examples C.5 and C.6). Paradoxically, in the Altenberg Lieder (op. 4), which do not ascend as high as Lulu, Berg did specify an alto trombone, although there are discrepancies between the autograph score and the Universal Edition publication regarding its usage. According to Dr Regina Busch of the Alban Berg Institute, Berg specifies four trombones, ATTB, in the general Besetzungsliste of the autograph.15 The Universal Edition score it is simply '4 Posaunen'. Moreover, the alto trombone in the published score is indicated on only two occasions: in Lied II (bars 6-7 and presumably 9, as shown in Ex. C.7) and in Lied IV (at bar 12, ending at bar 22, in Ex. C.8). According to Dr Busch, however, Berg calls for the alto trombone in all movements on the autograph score.
In the fifth Lied of the UE edition (Ex. C.9), the F and Ab in the first trombone part of bar 24 are bracketed, meaning that they can be omitted. As these notes are impossible (i.e. too low) to play on an alto, this seems to imply that the alto trombone, though not specified for this movement, was nevertheless intended. The autograph is equally ambiguous.16 Designating the first trombone 'Alt (Tenor)' in the fifth Lied, Berg brackets the F and Ab in bar 24 and thus seems to suggest that if an alto is used rather than a tenor, the first two notes should be omitted. Yet a trombonist would hardly choose to perform this passage on an alto as it ascends only to the note e and is far more practical for a tenor trombone.17 Indeed, the same can be said for all but five bars of the entire piece, including passages in the second and fourth movements. Since much of the trombone part is either muted or in a nearly inaudible pianissimo, it seems unlikely that Berg was utilising the instrument for the sake of its tone colour. Berg's curious scoring for the alto in this, his earliest work for large orchestra, suggests perhaps that he was uncertain whether a trombonist could be asked to double on the alto and tenor during the same work.18 Moreover, according to Kunitz:
Ganz allgemein ist zu beachten, daß heute kein Spieler mehr ausschließlich auf die Alt-posaune spezialisiert ist. Die Altposaune wird vielmehr nur im Bedarfsfälle von den Tenorposaunisten übernommen, wobei sich diese jedesmal auf die kürzeren Positionsabstände der Altposaune umstellen müssen. Welche technischen Ansprüche hierbei an die Posaunisten gestellt werden, zeigt sinngemäß die Tatsache, daß nur sehr selten ein Spieler zwischen der Violine und der Bratsche alterniert.19
Kunitz's opinion notwithstanding, the statement by Del Mar in regard to the first trombone part of the Drei Orchestertücke that 'the player... will use either the alto or tenor according to range'20 is equally applicable to other works by Berg.
One might regard with surprise Dr Mark Hartman's contention that 'there is no indication in the score'21 of Mahler's Seventh Symphony of the use of an alto trombone, since Mahler specifically wrote in the autograph score that a four-bar 'sehr weich geblasen'24 (see Ex. C.10).
The following passage, occurring at bar 146 in the last movement of Mahler's Sixth Symphony, includes the rather curious instruction 'auf Alt-Posaune zu blasen',25 presumably to facilitate reaching the a' in pianissimo, although Mahler required higher notes from the tenor trombone in this and earlier symphonies. Moreover, since the trombone part is played in octaves with the first trumpet, both con sordino, one does not feel the composer was using the alto in order to exploit its unique timbre (Ex. C.11).
A number of professional trombonists oppose using the alto as an upper-register aid. Glen Dodson, former Principal Trombonist of the Philadelphia Orchestra, is one. Dr Hartman reported that Dodson:
believes that trombonists many times use it because it makes notes in the high register easier. Some trombonists have difficulty, and they resort to the alto trombone. He maintains that this is not a good reason for the use of the alto trombone.26
Schoenberg, on the other hand, used the alto trombone primarily to add to the panoply of orchestral tone colours. Yet the powerful dynamics that he frequently demanded of the alto trombone within a large orchestral context – a function for which the instrument was not designed – often leads to a forced shrillness, resulting in a distortion and loss of its unique timbre (Ex. C.12, C.13, C.14).28 as seen in Ex. C.15.
The slide technique and the instinctive familiarity with alternate positions that Schoenberg requires – unlike anything previously written for the alto30 one wonders whether first trombonists originally performed these parts entirely on an alto, or whether the instrument was reserved for the occasional high note.31
However, the following passage from Gurrelieder (Ex. C.16) could not be played on a tenor trombone, as Schoenberg clearly realised, because a glissando between eb' and a is only possible on the Eb instrument. Schoenberg explains in the score:
Glissando der Posaunen wird folgendermassen ausgeführt: das Es wird als Oktav des 'geschlossenen Zuges' mit den Lippen fixiert und dann das Rohr ausgezogen respektive wieder zusammengeschoben.32
In Pelleas und Melisande (composed 1902-1903) Schoenberg used the alto rather curiously, rarely assigning it passages in the upper register, its distinct tone colour further obscured by frequent doublings. Robin Gregory states that Schoenberg used the alto trombone in Pelleas und Melisande 'as if uncertain of its capabilities... It is not clear why it is used'33 (Ex. C.17).
Thanks to the creative use of the instrument in chamber works, such as Stravinsky's Threni (1957-58) and The Flood (1961-62), Benjamin Britten's Burning Fiery Furnace34 (1966) especially and to the growing appeal of the eighteenth century solo repertoire (not to mention orchestral doubling fees), the alto trombone has experienced a resurgence of interest on both sides of the Atlantic. The past decade or so has witnessed increasing use of the alto in those orchestral works which are perceived to have been written for it.35