Guerra's return to secular music, after the Christian-themed "Para Tí," is a romantic romp through multiple subgenres of tropical music, including bachata, merengue and salsa. On danceability alone, Guerra takes no prisoners. But what makes this album worthwhile is his ability to make tropical music transcend at a time when the vast majority of the output in the genre is, frankly, boring. "La Llave de Mi Corazón" embraces change with its title track, a bilingual mix of mambo and blues with clever, pictorial lyrics and sophisticated arrangements. From there onward, the album is a mix of more traditional Guerra fare—that is, midtempo romantic bachatas and fast-clipped merengues—but always boasting superior arrangements and inventive lyrics (the bouncy "La Travesía," a take on "You're the Top"). Guerra also spices things up with a couple of English tracks, icing on an already tasty cake. —Leila Cobo