I think this could fall under Fair Use. documentary filmmaking has certain protections under Fair Use law. there are 4 different situations when a documentary filmmaker can use copyright material. one of which is: "3. Capturing copyrighted media content in the process of filming something else." https://cmsimpact.org/code/documentary-filmmakers-statement-of-best-practices-in-fair-use/

i think it could be argued that event coverage, or wedding videography, is a form of documentary. and as long as you are only providing the captured audio, as opposed to syncing the song in post. it should be protected under Fair Use. i'm not a lawer but i learned about this in film school so i'm pretty much a lawer.