Back in 1975 ZZ Top sang that it wasn't asking for much. But it's received, and given, a great deal over its nearly 50 year history. The Texas trio, whose lineup has been intact since its 1969 formation, has released 15 studio albums -- the last, "Futura," came out in 2012 -- and scored enduring hits such as "La Grange," "Tush," "Gimme All Your Lovin'," "Sharp Dressed Man" and "Legs," among others.