Had a quick look at the app, I don't know the full scope of it but here is API URL for a song: https://v4vmusic.com/api/songs/cme2ggb7r02pzli1xtx4kwt9h

This again has a link to the original RSS feed: https://hogstory.net/uploads/everything_is_lit_feed.xml

This is a self-hosted artist I think. I found another that links to RSS feed at wavlake.

I'm adding basic RSS API in Nostria as well, which will aggregate music tracks and spit out an XML RSS feed. Though I probably won't add database caching for this backend API, at least not initially.

Nostria does client side RSS feed parsing allowing user's to consume a feed, but I presume you're wanting to allow users to come from other apps and import their content to Nostr, right?

If you want to do this style of app, I think you need a proper backend that stores the events and have indexes for search and lookup. If you're going to dynamically construct an RSS feed based off Nostr events it will be slow, which is what caster does I think? It often times out and gives errors, but it provides an RSS feed for npubs: https://castr.me/npub1wav4fae3gyfy3xj298kxj2mj8phavz7vavps34przq02j7w902qq902923/rss.xml