It's not often that San Francisco gets to see a potentially Broadway-bound new musical have its world premiere here, and when it's a musical about San Francisco based on a beloved serial that first appeared in the Chronicle in the 70s, well, that's a major aligning of the musical theater stars. Armistead Maupin's Tales of the City, which is the centerpiece of the season at A.C.T. and the biggest scale new work ever produced there, will not disappoint lovers of the books or the PBS mini-series from the early 90s. It's a joyous and almost fully realized piece of theater, with a terrific cast and at least three great musical numbers, and it is, by any stretch, a glorious celebration of the San Francisco of the mid-70s, in that moment of liberation and drug doing just before things turned darker with assassinations and Jonestown and such.