Par UBER. American composer, trombonist, conductor and teacher, David Uber (b. 1921) is a virtuoso performer on the Trombone, as well as a popular music professor. His 23 Virtuoso Clef Studies remain significant for Trombone, Baritone, Euphonium and Tenor Tuba players. Uber 's 23 Virtuoso Clef Studies were compiled in 1982 and address advanced musical techniques, including unusual time signatures, complex rhythms, accidentals, variations in performance directions, breath control, unusual intervals, complex key signatures, ornamentation and articulation, among other aspects. For all advanced Trombone, Baritone, Euphonium andTenor Tuba players, Uber 's 23 Virtuoso Clef Studies ensure progressive technical studies./ Etude / Trombone