The Crooked Road isn't really a thing yet. It's a nice concept, but you kind of need to put together your itinerary yourself because it hasn't quite jelled.

The festivals you should pay attention to:

Mt. Airy, North Carolina (Weekend after Memorial Day)
The Wayne Henderson Festival at Whitetop (sometime in June)
Elk Creek, Virginia (Weekend before the 4th of July)
Ashe County, North Carolina (sometime in July)
Galax, Virginia (2nd weekend in August)
Fries, Virginia (3rd weekend in August)
Laurel Bloomery, Tennessee (4th weekend in August)

The Floyd Country Store, The Carter Fold and the Fairlawn Ruritan Club (near Galax) are all kind of cool on weekends. The Blue Ridge Parkway music center has a concert schedule.

For singing, I don't know.

Museum, library type places are good at Ferrum and at the Bristol Birthplace of Country Music.

Good luck.