Do backward lyrics contain subliminal messages? The question was the occasion for media hype in the mid-'80s, when U.S. Republicans were playing rock records backwards to try to find some obscure meaning to the gibberish they heard (Led Zeppelin's "Stairway to Heaven" was an infamous example). Frank Zappa, as anti-Reagan as possible, probably thought the idea very stupid and created two pieces with backward vocals. One was "Won Ton On," the reverse version of "No Not Now" concluding Thing-Fish. The other was released on the 1984 album Them or Us under the title "Ya Hozna."
The vocals in "Ya Hozna" come from three different sources: outtakes from Moon Unit Zappa's "Valley Girl" session and bits from the 1968 "Lonely Little Girl" are collaged with the vocal track from "Sofa." The result makes absolutely no sense, but die-hard fans had a lot of fun deciphering the quotes. This montage was xenochronously copied over pre-existing music. The drums were probably recorded first: Chad Wackerman plays a rhythm pattern in 5/4. Bass, rhythm guitar, and lead guitar were added later; these follow a 6/4 time signature, creating a strange, uneven feel. The crunchy riff is topped by Steve Vai's inspired solo.
"Ya Hozna" is a studio construction. It was never played live, of course, and remains only a curiosity in Zappa's oeuvre.