Concertos for trombone are rare in the 18th century - that by Johann Georg Albrechtsberger being the only known companion piece to the present work. The concertante part specifies merely "Trombone solo," but the tonality and tessitura of the work as well as the use of alto clef strongly point to the alto trombone as the solo instrument. The use of tenor trombone is not precluded, however; and the use of a narrow-bore instrument with a small mouthpiece would facilitate the problems of range and of tone quality encountered here. It is suggested that the concerto might equally well be played on other instruments for which it is imminently suitable (e. g., bassoon, violoncello, and so forth).