I well remember those early 1970s concerts by Threadgill-Hopkins-McCall when they played nothing but, or almost nothing but, Scott Joplin rags. Those were down south at the University of Chicago, then the trio moved north to play weekly at the Jazz Showcase. (They replaced the weekly shows by Muhal's sextet, which included Threadgill, McCall, Kalaparusha, Wallace McMillan - that's about when Muhal moved to NY.) Threadgill-Hopkins-McCall were glorious together, so vivid - solos were high drama, they were telepathic. Plus Threadgill was composing marvelous songs. Rather miraculous that they sustained such closeness and immediacy for so long. Some favorite albums of the period were special favorites: Air Song, Air Raid, Air Time, and the Arista with the Morton songs.
Threadgill once said the reason he had 2 drummers in his Sextet was because it took two to replace Steve.