Used by the routines at LEAPER, REMOTE_ROBOT, CEILING_DROP, WANDERER, DROPPING_BLOCK, LIFT and MOVE_PLAYER.

Six waves at a half-wave count of the complement of 64 more than Z, rotated left twice (so the top two bits wrap round): the higher the object, the higher the note. The entry at BEEP_BY_A takes the value in A; BEEP_BY_U, BEEP_BY_V and BEEP_BY_UVZ use it for U, V and all three. Knight Lore's sound_pitch_from_z and sound_pitch_from_a.