1955
Walter Piston, inhis orchestration textbook, says, “The trombones are by tradition group instruments rather than soloists and they are used very frequently in three-part harmony, performing a harmonic background function similar to that performed by horns….The most suitable melodies for the trombones are those having a kind of deliberate dignity and solemnity, or those of a choral type that would be sung by more than one voice” (Piston).