The song was composed by Billy Straus of Putney, VT. He was the original producer for Rockapella and they should be considered as recording the "original" version of the song. Here's a confirming clip from a page by Sean Altman, a ROckapella member who was selling off some instruments:

Yamaha SY55 Synth Keyboard: $200
Long time Rockapella and Sean producer Billy Straus gave this to me. Billy produced Rockapella's first demos in the late '80s, and co-produced Rockapella's first seven Japan CDs for For Life Records. This was his studio keyboard, on which he composed the Rockapella classic Change In My Life, several co-writes with me (Falling Over You, I Found Suger, Change My World), songs he wrote with Elliott Kerman (Rock River, Holiday Groove), and the 3 Brave Woodsmen songs that Billy, David Yazbek and I performed on the two Carmen Sandiego albums. One key has a faulty spring; it works, but it sits lower than the others (can be repaired).