The beat the song is built on is a 2-bar phrase, played through bars 1-3, 5-7 and 47-49, and 1 more place -- 17.1% of every bar the kit plays. This one moves around more than most: the beat is where to start, not the whole job.
It is played on crash, snare and kick, counted in thirty-second notes. On its own it scores 75 out of 100 -- demanding -- and the thing that decides that is how many notes a second it asks for.
The whole song is 88 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 50 BPM -- and adds the notes back over 5 rungs, each with a tempo to reach and a gate to pass before the next.
Tempo goes 50, 60, 70, 80 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 2-bar phrase on crash, snare and kick, in 4/4 at 90 BPM, counted in thirty-second notes. It is written out above, and it covers 17.1% of the bars the kit plays.
Bars 1-3, 5-7, 47-49 and 51-53. The time is kept on the snare to start with, and it changes 11 times over the song.
75 out of 100 on its own -- demanding. The song as a whole is 88 out of 100. Hard, and what makes it hard is how many notes a second it asks for.