A variety of combinations of instruments can play trios with these books. With the exception of the basses, any three like-instruments such as three flutes, three clarinets, three cornets, three trombones, three bassoons, and so on can play together in three-part harmony. Numerous mixed-instruments such as violin, trumpet, and tuba also may perform all of the trios in these books. Basses must play the bottom line only, but the music is arranged so that they have the melody from time to time. Any number of instrumentalists may play together in three-part harmony. Thus, directors can rehearse the music with large ensembles and assign trios of players or groups of players to practice and perform together. / Tout Instrument