Where free jazz meets rock. Allman Brothers at (Fillmore East, 1970). Gregg Allman based his song Dreams on a two chord vamp over a 6/8 groove, which was more typical of free jazz than rock. Duane Allman’s solos, inspired by Miles Davis and Coltrane, abandon standard rock scales for mixolydian explorations. Dark Star by The Grateful Dead is another modal exploration. The Adventure in Ken Burn’s Jazz has more to say about free jazz. Listen to more jam rock music by the ABB and the Dead on Hoopla.