Last night I listened to the Mamas & the Papas eponymous second album, and I noticed a couple things about "No Salt on Her Tail." During the first instance of the "This little bird..." section, the "away" in the line "She can fly away" has a melisma. It's sung to an F, F, D, C phrase. That's more than the two syllables with which "away" is normally pronounced, so it gives a sense of the movement in the bird's flight.
In that section "away" is rhymed with "stay" (the lines are "She can fly away" and "No cage to make her stay"). The "make her stay" is all sung to the same note (an F), so again there's a mirroring of the lyrics in the music. Where "away" is sung to multiple notes and suggests movement, the phrase in this line about being stationary is sung to a single note.
This section is repeated near the end of the song (raised a half-step, which I hadn't realized until figuring out the vocal melody), but not all of these features are still in place there.
