The Soprano Trombone is a curious little instrument. It is pitched at the exact same range as a standard B-flat Trumpet and one octave above the Tenor Trombone, and therefore is often called a “Slide Trumpet.” In fact, it is trumpet players, rather than trombonists, who will be playing this instrument. It uses a standard trumpet mouthpiece, and aside from the technique of the slide over valves, the sound is almost indistinguishable from that of the trumpet. As such, unless glissandi are needed, it might be better to use a trumpet in its place as it is far more common and intonation will be more secure. It should be noted that we are wont to remember that trombone literally means “big trumpet.”
At one time it was speculated that a Soprano Trombone was used to double soprano parts in the choral music of Bach, but this notion has been discredited. Today, the Soprano is mainly used by jazz trumpeters looking for the ease of glissando and as the top voice in Moravian trombone choirs. If used, all available trumpet mutes should work on the Soprano Trombone. A side note, trombones even higher than the Soprano exist (the Sopranino and the Piccolo, the same range as the E-flat and Piccolo Trumpets). They are quite rare and of very limited value.
A demonstration of a Soprano Trombone