The Mothers of Invention – Absolutely Free (1967):  The Mothers of Invention was led by the one-of-a-kind Frank Zappa, a fabulously talented musician and bandleader who played a fierce guitar and combined everything from doo-wop to avant-garde classical music to jazz to orchestral soundscapes into what amounted to a new form of serious music.  Frank Zappa’s music can be a challenge to follow, never mind understand.  As if this were not enough, the music was layered with bursts of song lyrics that were often alternately absurd, humorous, and bitingly satirical, with frequent non sequiturs.  As much a concept as an actual band, the Mothers of Invention proper lasted from 1965 to 1969 and, like the backing band during Frank Zappa’s long solo career, was sometimes a rock band, sometimes an ensemble, and sometimes nearly an orchestra.  The debut album by the Mothers of Invention is a double album called Freak Out! that was released in July 1966, just one month after the first double album of the rock era, Bob Dylan’s Blonde on Blonde.  Their third album, We’re Only in it for the Money (1968) is packaged within an intricate satire of the cover of the Beatles’ landmark Sgt. Pepper’s Lonely Hearts Club Band (1967) – so much so that the gatefold was assembled inside-out, with the bandmembers pictured against a yellow background put on the outside.  Absolutely Free is the second album by the Mothers of Invention and opens with one of Frank Zappa’s better known early songs “Plastic People”.  Also featured is a compressed rock opera of sorts called “Brown Shoes Don’t Make It”.