Passatoni means something like: Let the tones pass.
You may compare it to the game, where you whisper some tones into the ear of another person. This person whispers them on to the next, who whispers them on … – and how do these tones sound, when 25 persons have heard them and passed them on?
The piece is available for both string orchestra and in a version with doupling winds. Both versions may be used by amateur orchestras.