A Night of Improvised Round Robin Duets (Wednesday) The art of spontaneous duologue gets a supersize platform in this special concert, a joint presentation of Red Bull Music Academy and Undead Music. Unfolding as an overlapping series of one-on-one exchanges, it will feature a staggering array of musicians, including Allen Toussaint, the New Orleans pianist and singer-songwriter; Marc Ribot and Nels Cline, the stylistically voracious guitarists; Amp Fiddler and Daedelus, the head-trippy electronic producers; David Murray and James Carter, both unstoppable saxophonists; and Wadada Leo Smith and Dave Douglas, both incisive trumpeter-composers. At 7:30 p.m., Town Hall, 123 West 43rd Street, Manhattan, 800-982-2787, the-townhall-nyc.org; $22 to $32. (Chinen)