Steve, You really have to decide what you want the jam to be. It seems like you have a group that's reasonably happy (25 sounds like pretty good attendance to me).

I think Rise Up Singing works well for groups that are primarily interested in singing. The major benefit is that everybody is (hopefully) singing from the same page. They also aren't being asked to sing alone (much). The effect is that there's a whole lot more participation.

But if you're going to have everybody sing that leaves a lot less room for playing. Assuming that you have a bunch of players that want to do instrumental solos. You might not be hearing solos because they aren't trying to do them . Although with your numbers somebody had better be organizing the solos.

jeff s (is 21 days long enough between posts?)