Braxton’s contribution to the 1970s vogue for double live albums is a gorgeous documentation of two quartets. On half the record, he’s joined by trumpeter Kenny Wheeler, and on the other half, trombonist George Lewis, with bassist Dave Holland and drummer Barry Altschul providing support throughout. On the longest piece, the nearly 24-minute “29 M 36,” the quartet with Lewis is augmented by the Berlin New Music Group in a meeting of complex jazz/improv and modern composition. The other pieces run the gamut from quiet, atmospheric explorations to bouncing post-bebop joy-dances.