Aufstieg und Fall der Stadt Mahagonny

Gyron's review is quite good. I'll just add a couple points.

I don't agree that "Jimmy" running out and harassing the audience is something good. Who needs that? But this is consistent with Brecht's philosophy of the stage, even if that touch wasn't actually specified. The theater is not there to entertain an audience (while perhaps offering insights along the way), but its purpose is to instruct and regiment. This leads to endless tendentious little explanations, just to make sure you "get it." Leftists claim they object to rightists "wanting to impose their values" but Brecht, a Communist, does nothing but tediously impose his values. His plays are really sermons.

BTW, as far as "showing the evils of Capitalism," this is a bit simplistic, but in addition: then Brecht was a supreme hypocrite. He made sure he was well-paid and that his royalties were secure by being owned by a Frankfurt publisher, not a DDR one. See chapter on Brecht in Paul Johnson's Intellectuals.