Wand (1995) recently extended his work on correctness proofs for sequential compilers to parallel languages.
The rate of triggering and duration of the notes can be raised and lowered within a certain range by moving up or down the wand while pressing its button.
I play with my wand.
Wand (1986) also records type checking decisions, focusing on function applications as the loci of type errors.
The two first modes allow each wand to perform a different instrument independently.
The rest of the division marked the time by touching, with their wands, the accent marks in their books.
The third uses both wands to control a single instrument.
By moving up and down the wands it is possible to obtain perceptible bend effects.