is derived from the calls on the chorus sung by Maurice accompanied by Colin's drumming, and Barry sings the verses and plays guitar.

(Pentangle drummer Terry Cox added drums on the October 8 sessions)[4] Maurice claimed that the song was not even quite finished, but it still had Barry's guide vocal on it.

The song also is notable for being the only Bee Gees A-side single to feature any vocal solos from Maurice Gibb, these comprising the "I.O."

Cash Box stated that the song "introduces a new sound to the act, more tempo and rhythm effectiveness...and a melodic shift that shines a new light on the group.

[8] According to Bee Gees biographers Melinda Bilyeu, Hector Cook and Andrew Môn Hughes, "I.O.I.O."