The Los Angeles trio Black Eyed Peas are the latest crusaders of alterna-rap in a hip-pop world. Their debut album, Behind the Front, offers an organic mixture of sampled melodies and live instruments aimed at those of us seeking a little enlightenment with our well-oiled boogie. Front really takes off when the Peas challenge the status quo or indulge their braggadocious taste buds; the trio defends its nonmaterialistic credo (“Fallin’ Up”), warns society of urban chickens coming home to roost (“Karma”) and just plain differentiates between good and evil (“Positivity”). On the introspective “Duet,” rapper Apl.de.Ap warns, “Don’t get close to me if you are contaminated/Take a picture of your soul and get it laminated.” The Peas meet their party quota with the hardcore “Joints and Jams,” the stutter-stepping “Head Bobs” and the Meters-sampling “Clap Your Hands,” Front is not without a few generic-sounding songs — the loincentric “The Way U Make Me Feel” and the Busta Rhymes copycat track “Be Free” — but they don’t mar this ambitious effort. Enjoy some soul food.