The not-so-secret weapon behind Celia Cruz's seemingly endless reign as queen of salsa is her unstinting consistency. The three-time Grammy winner tours like she's drawing breath and churns out a new album almost every year without fail. Last year's La negra tiene tumbao (Sony Discos) only reinforces her commercial steadiness; it's full of brassy, hard-driving salsa that doesn't let up for a minute. In recent years she's begun to take a few creative chances in the name of demographic expansion, fusing salsa with more contemporary styles. The amped-up title track of the new album, for instance, merges an electronically enhanced Latin groove with stuttering dancehall beats and some Spanish-language toasting from Puerto Rican guest Mikey Perfecto. But otherwise she doesn't disappoint her salsa-loving constituency, and neither does the production work of old pros Johnny Pacheco, Sergio George, and Isidro Infante, who expertly rub out most of the music's Cuban, Puerto Rican, and New York accents. The horns are loud and punchy, the polyrhythms thick and propulsive, and the montuno piano passages hypnotic and precise, but in every case it's Cruz's voice that commands attention: over the decades it's deepened and lost some of its flexibility, but it can still cut through the arrangements like a knife through soft butter. Her live sets rarely veer from time-tested favorites, but they don't lack quality. I just wish they weren't so, um, consistent. Wednesday, July 17, 8 PM, Pavilion, Ravinia Festival, Green Bay and Lake Cook Rds., Highland Park; 847-266-5100.