I also love the Silly Sisters. How about something slow to get started like "GREY FUNNEL LINE". What kind of accompaniment do you use? For old-timey stuff, I agree that you can't go wrong with the Carter Family and they may very well work out great if you're looking in your local library. Although they are a trio and get kind of complex, the group "Voices" with Cindy Mangson,(forgot the others) are wonderful.