“On no account 3 tenor trombones! One genuine little alto trombone and, if possible, also a genuine bass trombone” (“Daß keine 3 Tenor Posaunen kommen! Eine ächte kleine Alt-Pos. u. wo möglich auch eine ächte Bass-Pos.”) (emphasis in original; Avins 127, 136).

(Avins and Eisinger point out, incidentally, that Brahms deliberately misspells the word echt as ächte in order to mimic the local dialect [Avins 128]).

It may be worth pointing out the similarity of Brahms’s request with that of another important composer of the era, Hector Berlioz. Less that 30 years earlier, Berlioz demands a “true alto trombone” for Symphony Fantastique (Trombone History Timeline–1830): “The alto trombone part must not be played on a big trombone, as is often done in France: I demand a true alto trombone.”

The Brahms quotation would seem to suggest that Brahms may have had an affinity for the alto trombone and bass trombone. The Brahms and Berlioz quotations together would seem to indicate that the “true” or “genuine” alto trombone of that time was “little” (and not simply another tenor with a small mouthpiece; Berlioz describes it as an instrument pitched in E-flat in his orchestration treatise), and that there were prominent 19th-century musicians who had some fondness for this “genuine little” instrument.