Like much of the material that came out under Frank Zappa's name in the late '70s, 1979's 'Sleep Dirt' has a complicated history. Also like much of the work that ended the artist's most prolific decade, 'Sleep Dirt' had its roots in a shelved, four-LP set that Zappa's record company refused to release.

It all stemmed from a 1976 falling out with manager Herb Cohen, who co-owned, with Zappa, DiscReet Records, a label distributed by Warner Bros. After Zappa's relationship with Cohen soured and they ended up in court, the record company temporarily sided with Zappa and allowed him to release some projects without Cohen.

In 1977, Zappa gave Warners an ambitious four-album set called 'Lather,' which was made up of various material recorded over the past eight years. Naturally, the bottom-line-minded company balked at releasing such an uncommercial project, which was kinda Zappa's kiss-off farewell to the label anyway, since he was contractually obligated to deliver four more albums before he was free to do what he wanted. Plus, Warners was now siding with Cohen.

So Zappa returned to the editing room and split 'Lather' into four separate albums: 1977's 'Zappa in New York,' 1978's 'Studio Tan,' 1979's 'Orchestral Favorites' and 'Sleep Dirt,' an entirely instrumental LP combining his usual mix of avant-rock, jazz-fusion and proficiently played prog. After more back and forth with Warners, the label eventually decided to release the records, but without Zappa's input, which meant that liner notes, cover art and other details were left in the hands of neglectful company suits.

So, the seven-song set, as released, was both a compromise and a middle finger. With songs like the seven-minute opener 'Filthy Habits' and the 13-minute closer 'The Ocean Is the Ultimate Solution' bookending the album, 'Sleep Dirt' doesn't sound as disjointed as its origins let on. And the title track remains one of Zappa's best instrumentals from the period.

But the material was better served on 'Lather,' which finally saw official release in 1996, three years after Zappa's death. Five 'Dirt' songs were supposed to be on the shelved project, albeit it in slightly different forms. Plus, the abridged 'Sleep Dirt' itself was originally called 'Hot Rats III' by Zappa before Warners put a stop to that too.

So, as far as these sorta things go, it's not a bad album. But its showing on the chart -- it stalled at No. 175 -- was the lowest of the quartet of albums restructured from 'Lather.' A few months after 'Sleep Dirt''s January release, but before 'Orchestral Favorites' came out, Zappa released 'Sheik Yerbouti' on his own Zappa Records. It made it all the way to No. 21, his second-best showing on the album chart, and marked a major victory in the singular artist's groundbreaking career.

Listen to Frank Zappa's 'Sleep Dirt'

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