The song originated from Mike for sure... The vocal melody is probably Peter's though. You can hear the similarity in this one from Mike's first solo album:https://www.youtube.com/watch?v=weI6qSg9OOE
― PaulTMA, Sunday, 24 October 2021 15:26 (two years ago) link
very credible-sounding thread on Who Wrote What:https://www.genesis-news.com/forum/index.php?thread/129-who-wrote-what/&pageNo=1
― PaulTMA, Sunday, 24 October 2021 22:23 (two years ago) link