Ask HN: Service for audio background music for videos

I have a site that allows users to upload video. I would like to give them option to select for a list of royalty free background music.

Are their any companies that provide a service like this? I’m currently use Transloadit for handling the video upload/transcoding and converting my videos to HSL for streaming. I know Transloadit has an option for merging separate audio tracks so I could leverage that. I guess what I really need is a nice UI for the user to select background music.

Thoughts?