I was having trouble visualizing a timpani as Michael desired, but you made it all work, Blaire! Great job.
Thank you, luderart : Having some decisions made for you generally makes things easier. I enjoyed writing this because it was one of the quickest and least fussed over things I've done. As for timing, composers have, for generations, counted BPM for timing/tempo, and relied on conductors to make music fit to other media. Now, of course, their is software to help with this.