One of the less common chord qualities is "root only". For example, the intro and bridge in Groove Yard have a plain G on beats 2 and 4. This could be done with a new chord quality called "root only". Otherwise there is really no way to play this tune with iReal. It doesn't work if there is a chord in those bars--that really makes it a different tune. Here is the standard lead sheet for Groove Yard:

http://www.guitarcats.com/realbook-j...ds/groove-yard