The beat the song is built on is one bar, played through bars 7-8, 10-11 and 13, and 18 more places -- 28.2% of every bar the kit plays. That is the spine of it; everything else is what happens around it.
It is played on crash, hi-hat, snare and kick, counted in thirty-second notes. On its own it scores 37 out of 100 -- a fair first song -- and the thing that decides that is how fine the subdivision is.
The whole song is 77 out of 100, so the beat is not the hard part: what costs you is everything around it, the joins and the fills.
A part this hard is not learned by playing it slowly and hoping. The room opens it on its simplest reduction -- the timekeeper alone, at 68 BPM -- and adds the notes back over 3 rungs, each with a tempo to reach and a gate to pass before the next.
Tempo goes 68, 79 and 90 BPM, and the gate at each one is 8 loops in a row with no wrong note and no wobble in the time.
PRACTISE THIS BEAT →A one-bar groove on crash, hi-hat, snare and kick, in 4/4 at 90 BPM, counted in thirty-second notes. It is written out above, and it covers 28.2% of the bars the kit plays.
Bars 7-8, 10-11, 13 and 15-19, and 17 more places. The time is kept on the silence to start with, and it changes 23 times over the song.
37 out of 100 on its own -- a fair first song. The song as a whole is 77 out of 100: demanding, mostly on how much of it falls off the beat.