He could use longs to do the calculation and be a lot faster.
True. Although float multiplication is faster that float division, which only needs to be done once.
Blanket or not, reading twice and ignoring the first is going to work, but it is so slow -- not even 5 good reads in a whole millisecond!
True. But, I'd still prefer to know exactly what kind of sensor is being read before offering advice on the "best" way to read it.
He could also time how long a digital pin is held high by his circuit to get analog reading.
Hmmm. Wouldn't that depend on the type of sensor? I can't see how that would work with an accelerometer, for instance. Or a flex sensor. Well, maybe with a flex sensor I could, as long as the sensor dropped back to 0 when the drum was not being hit.