It seems clear to me that your band members are just that. You pay all the recording expenses therefore you benefit from future sales. Anyone contributing to the recording should be paid for their work by the day/hour, as is usual in the studio.

Most musicians would prefer a clear cut, simple arrangement and money in their hand, rather than a promise of a share of future sales anyway (unless you're the triangle player on the latest Rolling Stones album!), but I do believe that they should be paid at the time of the work carried out.

Your comment about paying them "after expenses are covered" seems wrong to me. These musicians are surely part of the expenses of the production, to treat them differently suggests they would be more entitled to a royalty payment and you'll find yourself back where you were with the last C.D.

If your band thought that they were making an album then they would be sharing the work-load and costs as a band, and opening a joint account to distribute any future money received.

Good luck

C-flat.