Montana is structured in an unorthodox way (intro-verses-chorus-solo-middle section-verses-outro); from the beginning there are some interesting twists: there is an obligatory (written out) drum fill which leads to first verses. This became the song signature and one of Zappa's most acknowledged compositions.
The lyrics, sung by Zappa in a humorous manner, talk about a person who decides to go to Montana to grow "a crop of dental floss" (he's referring to the silk floss), mounting a pony named "Mighty Little". He dreams to become a "dental floss tycoon", by commercializing it. The verses are filled with pseudo-ranch pronunciation and are very lighthearted if compared to the lyrics of other songs in the album.
At 1:55, right after the chorus, Zappa plays a long guitar solo. Then, there's a complex middle section with vocals (performed by Tina Turner & The Ikettes, uncredited) backed by percussions singing some of the verses. Zappa follows singing the last verses and finally there's the famous coda, where the line from the chorus ("Moving to Montana soon...", sung by Tina Turner and the Ikettes) is repeated constantly and answered by a high-pitched "Yippy-Aye-O-Ty-Ay" (sung by Kin Vassy) , quite possibly one of Zappa's most memorable tunes. This goes on until it fades out towards the six-and-a-half minute mark.
Montana quickly became a fan favorite and was often played live, especially during the 1973-1975, 1982, 1984 and 1988 tours. On stage, Zappa often altered the lyrics of the song and sometimes even the structure, to great extent. The version featured on You Can't Do That on Stage Anymore, Vol. 2 ("Whipping Floss") is a perfect example: before the song starts, a fan asks them to play The Allman Brothers Band's song "Whipping Post". Since the band doesn't know the song, Frank (after playing a couple of jokes on the guy and the audience) chooses to play "Montana" instead, yet he alters the lyrics, which later forces George Duke and Napoleon Murphy Brock to pay attention with the vocal backing (and they do fumble at one part). Meanwhile, at the beginning of the song, the band starts playing very fast, which causes Ruth Underwood and Chester Thompson to stumble at the drum fill, leading to more jokes from the rest of the band. The end of the song is a very long guitar solo, that around 9:55 turns into some kind of funk jam, and finally segues into a short version of "Big Swifty".
The song (with the solo edited out) was the B-Side of "I'm The Slime" (1973) and many years later, put on the Strictly Commercial compilation.
According to Barry Miles' biography Zappa, Tina Turner was so impressed with a rough cut of the song, she volunteered herself and her backup singers to sing the "raising my lowly dental floss" backups on the song. Afterwards, Tina called her then-husband Ike Turner into the studio to listen. According to Miles, Ike listened for about a minute, declared "What the hell is this shit?", and left.