I'm the Music/SFX Director for a media marketplace called Pond5, which host tons of user generated music, video, sound effects and photos that can be licensed to content creators for use in all sorts of productions and projects.
We've got over 100,000 music tracks that are considered "cleared for sampling," which means they can be sampled, edited, remixed, sung or rapped over, manipulated, etc. The vast majority of these tracks are instrumental production music, including beats and isolated instruments in a ton of different genres.
Every Pond5 license is worldwide, in perpetuity, and across all media (meaning the track can also be used in a TV show, web series, podcast, etc. forever, wherever, whenever). License prices start at $15 (there are over 40,000 Cleared for Sampling tracks for $15) and checking out is super easy.
You can check out some of Cleared for Sampling tracks here: https://cutt.ly/Op8Puck
You can also get started by going to Pond5.com, selecting "Music" from the dropdown menu, then clicking both the Cleared for Sampling and Non-PRO checkboxes under "ADDITIONAL FILTERS" on the music search page to view the Cleared for Sampling tracks.
Let me know if you've got any questions - feel free to reach out to me at firstname.lastname@example.org