A musical about a clawing, calculating whore, a thuggish dictator and a maniacal chameleon of a freedom fighter--I'm talking about "Evita"--requires much more than acting, singing and dancing from its three principals. That slippery quality known as stage presence (a k a charisma, star power) is an essential here; otherwise, Andrew Lloyd Webber and Tim Rice's melodramatic fable about Argentine first lady Eva Peron, hubby Juan and Che Guevara comes off as an overheated, hollow, noisy rant about the vagaries of celebrity.

To say that the three stars of the touring production of "Evita" playing through Sunday at Wolf Trap lack sufficient stage presence is a gross understatement. Natalie Toro can't seem to decide whether to play the title character as a New Yawk kewpie doll or a witchy virago, so we get a combination of the two. Her brassy singing and excellent diction keep her many numbers afloat, but her attempts at playing the seductress or dying a lingering death are painful to behold. It's hard to blame her entirely for her lackluster scenes with Juan Peron (Raymond Jaramillo McLeod), though. McLeod, a hulking he-man with a powerful bass voice, sends forth not a shred of sexual energy or menace. In fact, he barely moves his mouth while singing.

On the other end of the spectrum, there is the frenetic, mugging Raul Esparza as Che. A Jonathan Pryce wannabe, Esparza possesses none of the slinky, slimy intensity of that wonderful British actor. Wheezing dorkily through the action, he tries desperately to be sharp and satiric but lacks the timing and the discipline to pull it off. At times he affects an irritating English accent, mostly when snarling his way through the score's interminable recitatives.

The very best thing about this production is the 29-member ensemble backing this trio. Their majestic voices, impeccable articulation and gestural clarity make for some thrilling moments. And though they don't have nearly the requisite movement abilities to slash and ooze through Larry Fuller's evocative choreography (Fuller, who did the original Broadway choreography, also directed this production), the group does indeed conjure up a sense of the control and chaos, the military and the masses that is so basic a part of "Evita's" dramatic construct.

Musical theater at the barnlike Filene Center never works very well; the size and width of the venue, and the fact that the shows begin when it's still daylight, detract from the intimate, escapist qualities of the form. "Evita's" opening poses a special problem; the first scene has a crowd watching a black-and-white subtitled film that we as an audience are also meant to see. Suffice it to say that things work better after the sun has gone down. The sound system is also less than perfect--Tuesday night's performance suffered from a tinny and bombastic orchestral blend and muddy vocal amplification.

Evita. Through Sunday at Wolf Trap's Filene Center. Call 703-218-6500.

CAPTION: Natalie Toro as Eva Peron and Raul Esparza as Che in Wolf Trap's "Evita."