Original 1st printing 15 x 22" concert poster for Chicago appearing with the Allman Brothers Band (featuring Duane Allman and Berry Oakley) and Edison Electric Band at the Spectrum in Philadelphia, PA on 8/12/1970.

 Artist unknown/not credited, medium-thick glossy-coated index stock poster is in excellent (B+) condition; aside from a soft 1 x 2" diagonal stain in the lower left corner tip, a couple of nearly-invisible stress bends and light pin-prick surface spots here and there and a trace of tape residue on the reverse, this example is just about as sharp as they come.

 ULTRA uncommon low-run regional Duane/Berry-era Allman Brothers concert poster from the legendary Philadelphia Spectrum.