A note about couple of interesting theatre performances are going on right now: Are you my negative space? and The Girl in the Flammable Skirt.

Are you my negative space? is a show about comics, war, and love. The live action cartoonists ensemble founded by Northwestern alumni combines performance, onstage drawing, music, and interactive video Athenaeum Theatre, third-floor studio theater, 2936 N. Southport, 312-902-1500. Opens Friday, November 21, 8 PM. Through December 13: Thursdays-Saturdays, 8 PM; Sundays, 4 PM; no show Thursday, November 27. $15.

Palio Productions is having a cheap (or free) ticket special on Friday night's performance of their new show The Girl in the Flammable Skirt. If you tell them you celebrated Buy Nothing Day (and buy nothing on Friday), they'll let you in for free. Side Studio Theater, 1520 W. Jarvis, 8 pm, reservations at 773.972.0492.