I thought about doing something like that and asked a few of my 4th grade students what they thought. We do one-month after school clubs so I would open it up to whoever wants to join the club. One hour, once a week. We’d probably have some fun group time with easy songs (and accompaniment), some duets/trios, and then a group piece. Of course we’d hold a recital at the end. But being such a short time commitment (and volunteers only) i don’t think I’d require practice sheets like we do for class recorders. The 4th graders liked the idea and want to sign up for the club!