Learning to play in different keys-especially different chord shapes. Is very important. You never know when someone will call out a tune you know in a key you've never played. Especially if a woman is singing lead. Their range is usually quite different. They need to sing what's comfortable for them, and it's our job to follow the leader!
This is a perfect example of tasteful waltz playing in the lower register of the banjo. Scruggs uses hammer-ons, slides, and pull-offs to create a fun, yet difficult arrangement of All the Good Times are Past and Gone.