"21 Guns" is an anti-war power-ballad by Green Day. It was nominated for two Grammys in 2010—in the categories of Best Rock Performance and Best Rock Song.
This beat is taken from the choruses, first heard at 1:05. Drummer, Tré Cool, uses both floor toms with the bass drum to create a thunderous rhythm that was designed to shake a stadium! He pedals the hi-hat in eighth notes to maintain momentum.
On the staff, the cluster of notes representing both floor toms and the bass drum looks like a bunch of grapes hanging from a vine (see image). The second floor tom note is pushed to the right hand side of the stem for clarity, however all three notes are played together.