The Sacred Harp, Ye Olde New-England Psalm-Tunes, The Southern Harmony and Musical Companion: these ancient "tunebooks" form the basic repertoire for countless musical groups that keep the tradition of "shape-note" singing alive. Longtime friends and collaborators, trumpeter Dave Douglas and pianist Uri Caine, reunite as a duo on this recording, exploring these 18th and 19th century American songs and their influence on jazz and popular music.