So the music would be hosted on nostr.build if I understand correctly ?
post the raw file to the nostr timeline and add the RSS Feed that castr.me gives you to a podcasting app. PodcastGuru handles these well and has video.
https://castr.me/npub1tn2lspfvv7g7fpulpexmjy6xt4c36h6lurq2hxgyn3sxf3drjk3qrchmc3/rss.xml
heres a movie from that feed right in that app.

Discussion
Yes. For that you would want to compress to mp3 or AAC, depending on what's supported. Higher quality mp3 vbr, or AAC.
I know nostr.build supports mp3. I've uploaded them before.
Does that only work with a paid nostr.build account?
I'm pretty sure mp3 is supported on free tier.
nostr:nprofile1qqsglv2qkn5dmmuhee9cy8fywfu2rfp4xd3xy0myqg2gfvmjl9yqqrqpp4mhxue69uhkummn9ekx7mqpzemhxue69uhhyetvv9ujumn0wd68ytnzv9hxgqgkwaehxw309aex2mrp0yh8qunfd4skctnwv46qye8cpd can you co firm?
If it doesnt work... can I zap you and pay for a month of nostr.build premium for nostr:nprofile1qqsp3yzapfwkyw4cr2vt4xx9s27474lj2pkxhqyfqh79n826pv3fkzqpzpmhxue69uhkummnw3ezumrpdejqzrthwden5te0dehhxtnvdakqz9rhwden5te0wfjkccte9ejxzmt4wvhxjmcru0tqj?
Audio is supported and always has been. We even have a player https://e.nostr.build
If you have questions let me know. I used to rip and upload a lot of albums to what.cd 😂
yeah wherever your post lives. It just pulls in the mp3s, mp4s and mp4as from your nostr profile.