I have taught folk ensemble classes for many years. I have taught at community colleges, private schools, rec centers and in my own home.

Here's my advice.

1. Start with just a few people first. Build up the confidence level in the group. The goal is in my view training the participant to function musically in a group. This can be done with different levels of playing skill.

2. Basic rhythm players can start with strummning the chords to the tune on the beat. More advance players can work with bass runs on the guitar, counter-lines on the banjo and basic chords or single string harmony notes on the mandolin, and melody played slowly on the fiddle.

3. When singing, encourage everyone (including the best players to play simply and show their skills by using fill-ins between the melody notes of the song.

4. Every player has something to learn at a slower tempo. They can work on technique that can be later applied to a faster tempo. ie: bar chords, inversions of chords up the neck, complex picking patterns for the right hand if kept in time and blended into an accompaniment.

5.   When singing, the lyrics and voice are the thing. Everything else is subservient to it. This is true when there is a solo instrumentalist taking the lead. This solo can be traded off amoung the more advanced players.

6.   The unison style applied in Irish sessiuns or the Round Peak style of Old Time playing obviously requires most of the musicians to play the tune at the same time. Even so, an appropriate rhythm or bass accompaniment can enhance it. Not everyone has to play the tune.
If you have more than one fiddle or another melodic style instrument, a slow descant or counter-melody line can enhance the lead soloists.

7.   If you play Irish or Old Time it is essential to be aware that this has been traditionally dance music. Much of it is required to be faster to accomodate the dancers. This is a great goal. If you can play this music in time and folks can dance to it, you have somewhat mastered it in my view.

8.   The "slow jam" is a great idea whose time has come. It's the best way to ensure that people will "own" the music and feel a part of the folk music process again as they did in the early fifties.
We predicated the emergence of the Chicago Old Town School of Folk Music on that principle....anyone can learn to play and sing together...when we founded it in 1957.

9.    As soon as possible, all written materials should be ditched. The music can be internalized if the player or singer doesn't have a nose in the book. A good solution has been suggested, tape the class and practice with the tape at home. Better to practice with the class rather than a single player taping an example because that's the "real world"...learning to play in a group.

Frank