COMEDY REVIEW : HE DOES OK--FOR A COMIC WITH NO ACT

John Mulrooney gets a lot of laughs for a comic with no act. It’s an impressive--and depressing--distinction.

To headline at the Improvisation in Irvine, where Mulrooney kicked off a six-night stand Tuesday, you not only have to be good and experienced, but you almost always need to have logged some appearances on “The Tonight Show Starring Johnny Carson” and/or “Late Night With David Letterman.” There are very few exceptions, but Brooklyn-born Mulrooney is one.

More to the point, though, you aren’t likely to headline at the Improv until you have accumulated a strong 50 to 60 minutes of routines. So it was especially striking to see Mulrooney hit the stage for an hour--and present somewhere between zero and five minutes of actual material.

What did he do with the other 55 to 60 minutes of his set? He spent it interacting with the crowd in a wildly uneven, though sometimes masterful, display of improvisation (appropriate, no?).

You figure Mulrooney comes armed with a supply of stock lines and topics to pursue. But such lines quickly became jumping-off points for spontaneous sharp-tongued exchanges, indiscriminate barb-flinging and multiple running gags that provided the evening’s ups--and downs.

For example, Mulrooney opened by trying on audience members’ eyeglasses and ridiculing the appearance or prescription of the spectacles. Amusing enough, even though you would bet he uses the same lines on a nightly basis. But the second he heard the aristocratic-sounding name of one of the spectacled spectators, Mulrooney instantly transformed his face and voice into a dead-on impression of an insufferable snob: “So good to be with you lower-income people. . . .”

It played funnier than it reads, but it’s representative of Mulrooney’s lightning-fast improvisational skills. But even if he had been consistently on-target--and he wasn’t--this kind of approach is too one-dimensional to hold up for an hour.

Even a little broadening--a bit more of his animated slapshtick and a lot more written material--would make a huge difference, the difference between a talented guy who appears to be slumming and one who could operate at the upper level of stand-up.

Worse, Mulrooney’s current approach relinquishes control of the performance to the crowd, another danger of building an act so heavily around interchanges with the audience. In his final minute, he noted, “We’ve lost all semblance of a show.” All too true.

(None of this is to say that his act didn’t go over extremely well, though toward the end response became pockets of applause and laughter rather than reactions that swept the room.)

Al Lubel, who preceded Mulrooney, also interacts with the crowd. And does it well. But Lubel, a one-time local boy starting to make very good (he headlines most clubs across the country now, has been on CBS-TV’s “Morning Show” and just won the semifinals of “Star Search”) not only has an act, but a very solid, well-written and varied one.

His 25-minute set ranged from singing (his set-closing tune is called “I’m Al Lubel”) to such clever observations as his pondering the entrepreneurial wisdom of owning change machines (“ . . . I’m thinking: What kind of businessman came up with these machines? Was he looking for income? Can you see this guy at the end of the day--’I broke even ?’. . .”)

An attorney, he’s capable of doing some material on law from a first-hand perspective, mostly puncturing the pretenses of lawyers or poking fun at his own career path. (“I know (giving up law for comedy) isn’t a logical move to make, but my clients convinced me I was a better comedian; they’re in jail right now, saying ‘Boy, that guy was a riot!’ ”)

But Lubel isn’t merely a riot. He also takes chances on stage, incorporating a brief bit on death and ways he could die (which worked and got laughs), and on the fleeting feelings and impenetrable emotional barriers that can characterize even the most powerful romance (too philosophical to get many laughs, it was nonetheless poignant and adventurous).

As the middle act, Lubel (who lived on Balboa Island before moving to Hollywood) had to keep his performance short. But it was long enough to see why his career is clicking: He’s very good, and getting better.

The bill featuring Mulrooney, Lubel--and opening act Vanda Michaels--continues at the Irvine Improv through Sunday.