A DVD revealing the recording of Frank Zappa's classic albums "Over-Nite Sensation" (1973) and "Apostrophe" (1974) is set to be released on May 1. Simply entitled "Frank Zappa CA Apostrophe / Over-Nite Sensation", the 98-minute documentary gives a rare insight into the work of the mysterious legend who died in 1993.

The Zappa family opened the doors to his UMRK Studio (Utility Muffin Research Kitchen) and the vault for the archive materials which feature rare performances, interviews with wife Gail, children Moon, Dweezil and Ahmet, and friends and colleagues including rocker Alice Cooper.