Rock en español is exactly that, rock in Spanish, unless there's something beyond language to set it apart.

And that's what makes Colombia's Aterciopelados so special.

They're very firmly aware of their roots, and bring them in often, to good effect in their music.

This best-of collection traces ten years of music, and Aterciopelados' evolution from a good alternative rock band to a group with a real vision.

It really all kicks in with "La Estaca," which shows that the passion that occurs in ranchera and rock can be combined in music, then with tracks from 1996's La Pipa de la Paz, which was musically adventurous, not just for its successful merging of son and hip-hop on "El Estuche," but especially on "La Culpable," where electronica and traditional Colombian forms and instruments come together for a while and make an excellent song, and their relatively faithful cover of Don Leonidas Plaza's "Baracunátana." Also fairly faithful -- but with its bolero feel heavily accented, is their version of Queen's "Play the Game" ("Juégale Apuéstale") -- an oddity that actually works well, never feeling out of place in its development.

It's fascinating to hear how singer Andrea Echeverri's voice increases in confidence and style through the years, and how bassist Héctor Buitrago focuses the sound.

It's apparent that quantum leaps have been par for the band -- witness the change with tracks from the Caribe Atómico album, where electronica came fully on board on the title cut, or "Maligno," as the band reworks and updates an Argentine style, accordion, Marc Ribot guitar, and all, with a full measure of aching, but never forgets where it originated, both rhythmically and melodically.

Grammy-winning album Gozo Poderoso is represented by three cuts, none of which have the real distinction of earlier cuts, and seem to mark the record as a holding action, as the band decides where to go next.

But the bonus cuts don't necessarily offer that many clues.

"Mi Vida Brilla" is flowing pop with lush, U2-style guitar, "Tanto Amor" offers a collaboration of ranchera and '80s electro (thankfully, the ranchera wins out), and "Florecita 2003" looks back to their early career, in a total revamp of "Florecita Rockera," this time to a Colombian champeta rhythm (far more sophisticated and appealing than its punk-ish original), dressed up to go clubbing.

Ten years of Aterciopelados has been an exercise of head and heart -- there'll be more fun in the next decade.