music rights

It's very simple, as per your 3 members agreement whatever the returns you get must be shared accordingly. There will be a Royalty, any live concert conducted must pay. It's all depends upon you 3 as agreed. The person who left can relinquish the rights / royalties at his free will but, his / her name must be acknowledged and published.

If there is no such agreement, go to a Mediator (Reputed group in the same profession), and reduce such terms as agreement.

I also released a few songs, they were heard by some of my friends who said they were pretty good. It's great to create music products myself