The second attempt by the sitcom “30 Rock” to gain attention by performing its episode live was a mixed affair. In some  ways it was a static collection of sketches imperfectly spoken at times. In other ways, though, the episode was itself a salute to the joys of live television, as Kenneth locks everyone into a room and extols the highlights of live TV in the past – from a take off on “The Honeymooners” called “The Lovebirds” to a Dean Martin type program, “The Joyey Montero Show” and an Amos and Andy setup (with Jon Hamm in blackface alongside Tracy Morgan). It culminates in a “Laugh-In” like send-up and a telethon starring Donald Glover as a young Tracy).

Other guest castings, Amy Poehler played a young Liz Lemon, though she seemed more like that little girl she once played on “SNL” who said “Rick! Rick! Rick!” all the time. Jimmy Fallon played a young Jack Donaghy in the same scene, with Fred Armisen stealing the scene in a wig during the East Coast feed.

The big guest was Paul McCartney literally doing a walk-through to start the episode and to end it.

But Hamm’s return to “30 Rock” was key to understanding a timely “Mad Men” gag, in which Will Forte’s cross dressing character is lowered by wire to sing “Zou Bisou Bisou.” Considering the relatively small audience for “Mad Men,” it almost qualified as an inside joke.

A shaky camera and the flatness of video (as well as the locale – studio 8H, home of “SNL”) made the show seem like a ready for prime time “SNL” with its interlocking sketches and occasional focus by actors on cue cards (it’s like crack for Alec Baldwin, who otherwise showed great comic range in the show).

Though it ranked high in jokes, writing and surprise, the show did have trouble with story and pacing. But the adrenaline that fueled the live TV they celebrated, also in the end gave the comedy its own jolt.