Written and produced by the Bee Gees, “Chain Reaction” was recorded in 1985 by Diana Ross, featured on her album Eaten Alive. “‘Chain Reaction’ was never originally meant to be on the album,” Barry Gibbs explained in an interview. “It was the last song we cut. We’d done the whole album and Diana said, ‘Well, we still need one more song from somewhere.’ We had ‘Chain Reaction’ all along but didn’t have the nerve to play it to her because it was so Motown-ish that we were scared she wouldn’t go back there. Robin Gibb persuaded her by saying, ‘We think it’s time you did something that you would have done with The Supremes and not just Diana Ross.’ Once Diana had recorded it, she sat down and heard the playback and realized it was a credible tribute to the past.”
While the tune did not perform well in the US, it reached #1 in the UK, Ireland, Australia and Zimbabwe. There are modulations sprinkled throughout the song: just in the first verse it moves from B to Db at 0:56 and D at 1:11, returning to B for verse 2 at 1:43 and moving through the same cycle again. A shift to Eb occurs at 3:00, followed by a half-step modulation up to E at 3:15, and it continues to alternate between those two keys as it fades to the end.