The ’70s was a decade to be mellow. At least, that’s what it seemed like. People wore clothing and decorated their homes in mellow earth tones. And a lot of the music on the pop charts was definitely mellow. When I think of the mellow vibe of the ’70s, one song always comes to mind: “I’m Not in Love” by 10cc. It was released in May of 1975, right in the middle of the decade, and became one the British group’s three #1 hits in the U.K. “I’m Not in Love” also topped the charts in Ireland and Canada, just missing at #2 in the U.S. What really stands out about “I’m Not in Love” are the haunting multi-tracked backing vocals. Once you hear them, you don’t forget them. That could be why the song has been included on movie and TV soundtracks well into the 21st Century. Remember the beginning of Guardians of the Galaxy ? And the annoying repeated line of “Big boys don’t cry” that destroyed the midsection by mistake came courtesy of the band’s tone-deaf secretary, Miss Kathy Re...