Stravinsky invented the rock beat in 1913

In a piece that is strongly identified with and by ostinatos, the "Procession of the oldest and wisest one" section of Stravinsky's The Rite of Spring is the standout, both in terms of density and number of patterns present.

In 20 measures of music (about 40 seconds) Stravinsky combines a BUNCH of patterns (I forget the exact count, and a count is tricky because some are doubled); the following pattern in the percussion is the foundation. The bass drum and tam-tam start before this; the guiro enters at measure 13 (:20) of the section:

When I was studying this as an undergraduate, I made the (typical) mistake of getting lost in the score without listening enough. If you just look at the score, it appears that the percussion instruments are playing "against" the steady eighth notes in the rest of the orchestra. It is actually notated in 4/4 at the beginning of the section, making its significance on paper even less clear:

What is actually taking place is this: the eighth notes are triplets when heard against the percussion. The boom/crash that is set up by the bass drum and tam-tam is further supported by the scraping of the guiro. What is notated like this:

is heard as this:

Which brings me to the drum beat. If you substitute the tam-tam with snare drum and the guiro with hi-hat it sure sounds and looks a lot like this:

a "characteristic drum beat" from Wikipedia

So to me, the "Procession" sounds like a whole bunch of triplets over a huge back beat. Because that's essentially what it is. The notation is slick and misleading, but the effect is very plain.