Considering that son simply means "song," one can imagine a wide definition. Indeed, this homegrown Cuban music developed from numerous styles more than a century ago, though most featured the defining tres (a guitar with three sets of equally tuned strings). If that instrument is the definitive sound, Sierra Maestra is the band par excellence. Leaving their European recording base -- where they've spent their past four records -- the members of this nine-piece return home to capture their nation's soul. A collection of 14 classics falling under the son umbrella, it is a rich selection of how eclectic (yet how alike) Cuban folk music is. Take, for example, the sudden switch from the Beny Moré-penned "Santa Isabel de las Lajas," an upbeat, horn-driven dance tune, to the acoustic "Ausencia/Aurora/Se Fue/La Mora," a beautiful selection from the trova tradition. Trova is akin to the European troubadour, and judging by how intimate and touching this song -- this album, even -- is, we can understand Sierra Maestra's importance in the nostalgic formation of the Cuban spirit.