Florentine Pogen. Per the poster, this is a soundboard recording from a show at the State Farm Theatre in Harrisburg, 1974-10-29.

That's Napoleon Murphy Brock on vocals again, and I'm sorely tempted to start tagging these posts with individual band members instead of just "Frank Zappa" but man that would be a lot more bookkeeping. But seriously, Zappa had a whole lot of great bands over the years. Both Zappas have had a lot of great bands over the years, now.