Caution: Slick Surface

Gloria Estefan may be the most anonymous hit singer in pop music. Even though the Havana native has had more than a dozen hit singles, it would probably take a charter member of her fan club to identify the singer the first time one of her new records comes on the radio.

There’s no identifiable stamp to her voice a la the drama of Whitney Houston, the self-affirmation of Wynonna or the seductiveness of Toni Braxton.

So why was the capacity crowd so ecstatic during Estefan’s concert Thursday night at the Forum, part of her first tour in five years?

In the words of that pop philosopher Donna Summer, she works hard for the money.

Except for costume changes, Estefan was on stage for the entire 2 1/2 hours of a flashy, fast-paced performance that was divided equally between uplifting, party-time exuberance and intimate reflection.

Things started off with the petite singer being lowered from the Forum ceiling to the stage in a giant, birdcage-like device.

Within seconds of hitting the floor in her sparkling, tight-fitting evening gown, Estefan was off and--literally--running. With a horn-and-percussion-driven band supplying the Latin rhythms that give her music flavor, she moved about with the energy of an aerobics instructor--razzle-dazzle so crowd-pleasing that most performers would save it for their finale.

Before the evening came to a close, however, Estefan had taken breaks from the high-energy material to sing songs of family and faith, as well as tunes about the joys and tensions of relationships.

Through it all, she reached out to the audience with a warmth that makes the crowd seem like part of her extended family. She showed family photos on giant video screens during “Along Came You” and put a spotlight at the end of the ballad on her mother and 20-month-old daughter in the audience.

There were moments in the show when the music delighted (the disco fire of “Everlasting Love”) and touched (the idealistic sentiments of “Always Tomorrow”), but not enough. Ultimately, the anonymity extends from her voice to the material itself.

Rather than being innovative or revealing in the manner of the most captivating pop music, the majority of Estefan’s songs deal with standard pop themes in ways that rarely go beyond superficial emotions. They are catchy and accessible, but undernourished.

Even when she sings in Spanish, during a choreographed segment designed to capture the flavor of an old Havana nightclub, everything seemed too constrained. Her singing and manner lacked the fire or charisma of someone like Albita.

For the encore, Estefan performed “Reach,” the song she co-wrote with Diane Warren that was the theme of the Summer Olympics, and it was remindful of the conventional mainstream design of so much of Estefan’s music.

“If I could reach higher . . . , “ she sings at one point in the song. “Some days are meant to be remembered / These days we rise above the stars.”

You wish that Estefan could reach higher--or at least deeper--in her own music. She’s certainly got the ambition and drive to put together a striking musical package. But it needs a personal stamp.

Until she delivers one, it’s too easy the morning after her concert to wake up and ask yourself, “Who did I see last night?”

* Gloria Estefan performs Tuesday at the Pond of Anaheim, 2695 E. Katella Ave., Anaheim, (714) 704-2400, 8 p.m. Sold out.