As others have said, you should really back down. Support his desire (or not) to be in a band, but don't get into managing the band, picking songs, etc.
You can talk to him about what he wants to achieve, and give some advice on how to achieve it, but that's about it. If you control it, it won't be fun for him anymore.
You can talk to him about what he wants to achieve, and give some advice on how to achieve it, but that's about it. If you control it, it won't be fun for him anymore.