If Un Poquito Quema'o worked off the fire and energy of musicians enthused about cutting loose and playing, Sin Fronteras finds a more mature Sergent Garcia and his Locos del Barrio well in command of the studio milieu.

The fuller sound and more structured arrangements on the opening "Que Traigan la Salsa" are an immediate sign that the group has matured -- even the breakneck finale of "Seremos" is well controlled.

Salsa still dominates the raggamuffin and the lyrics again fall on the light side -- only the pleas of relatives searching for missing family members in Rubén Blades' "Los Desaparecidos" are overtly political.

"Gigante" is reggae in the classic mold with strong horns and bubbling organ capped by a great coda with a trumpet solo, while "Salsamania" crosses its signals with lyrics saluting the band's Latin side over a pure Jamaican musical foundation.

It's the kind of genuine salsamuffin move Sergent Garcia's crew couldn't have made before.

"Seremos," featuring the African duo of Amadou & Mariam, throws in jazz-tinged guitar licks and generates a strong Afro-Cuban feel that brings that ancient transatlantic musical connection full circle.

Garcia's serviceable vocals probably won't thrill serious salsa devotees, but that's not really his target audience, and the power and precision of the music makes Sin Fronteras a well-rounded, highly enjoyable disc that may induce rock and Euro-mix fans to take the salsa plunge.