"musical beats" refers to the rhythm or the regular pulse that you can hear in a song. It's like the heartbeat of the music that helps you keep track of the timing and feel the groove. Full definition
You are the centre of a mass celebration with bouncing creatures and an equally bouncing musical beat. (vrfocus.com)
As the movie begins, Eazy - E has established himself in the drug trade with a steadily rising income and accompanying dead - eye stare; Ice Cube walks around with a notebook, scribbling down poetry that will be transformed into lyrics; and Dre alienates himself from his mother by his pursuit of musical beats as a disc jockey at a local club. (dallasfilmnow.com)
Hans Zimmer's score reinforces the impression, using natural sound as inspiration for musical beats. (siouxcityjournal.com)