Hey, all. Just thought I'd share an excellently groovy (advanced) timing and independence exercise by the name of Flash Gordon Henderson that I have loved for years. It is written by Murray Gusseck of DCI fame. Although the exercise is for a modern drumline (snares, tenors, basses), it can easily be adapted to drumkit, such as by moving the accents around the toms and keeping the taps on the snare.
Here is a video of it being played by the Santa Clara Vanguard (the exercise starts at 2:30): https://youtu.be/2N0_4olvQWc
Here is where you can purchase the sheet music (you can purchase the full ensemble sheet music, or the one for just the snares or tenors or basses): https://www.tapspace.com/flash-gordon-henderson