It’s not every composer who will travel to Costa Rica to record wild howler monkeys for a musical score, but that’s just what Andrew Lockington did to create the score for the Dwayne Johnson action-adventure film “Rampage.”

The thrilling music to this box-office smash featured over 90 members of the American Federation of Musicians Local 47, recorded on the Newman Scoring Stage at Fox Studios, as well as a Ugandan children’s choir.

Check out incredible behind-the-scenes footage from the scoring stage as captured in this video on the making of the “Rampage” score, via Variety — and some screenshots of the musicians below!