So after seeing their videos in constant rotation on Mun2, I finally picked up the album. They are to reggaeton what Outkast is to southern crunk. The group is made up of a couple of Puerto Rican brothers, Residente Calle 13 (mc/singer) and Vistante Calle 13(instruments, backup vocals). Residente has a killer flo that's as variant as any English speaking mc out there right now. Their subject matter is all over the map (from what little I can decipher since they ARE spanish speaking). Sound wise, they're also all over the map. Reggaeton beats dominate but there's also some polka, salsa, rock, funk, tejano, punk, reggae and trip-hop mixed in their too. Really, if you're into hip/hop or "world" music, this is an act you definitely need to check out.