This song is a family affair, deriving its dreamlike sensibility from the ethereal vocals of Neil Finn's wife, Sharon Dawn Johnson. The song's coda benefits from the psychedelic guitar work of Liam Finn, Neil's son and long-time collaborator in the studio and onstage.
Finn told Spinner UK about his wife's contribution to this song: "She's done some aaaahs and oohs and various things in the past and I've always known she had a lovely tone in her voice, but it was Jim Scott's idea that the song Isolation might take a woman's voice in the second verse, that juxtaposition. And we tried it with her, and I thought it sounded beautiful."
"Sloop John B" is a traditional West Indian folk song, and it was a huge hit for The Beach Boys in 1966. They tweaked the lyric, "This is the worst trip since I've been born" to "...I've ever been on" as a wink to acid culture.