My story about this song.
First off, I can never remember which soft-rock Chicago song it was, as they all sort of meld together in my head. But based on the date I know it was this one.
Two years out of HS. Summer of 76. Quit my job at the local grocery store as I was going to start college that fall. Two brother and I went on a 2 week drive out west in our 65 mustang. Oregon and California. Some nights camped out, some in Motel 6’s.
Somewhere in CA camping out in the evening I remember the local radio station saying this was the most requested new release. I had not heard it before.
Got back. Went my Freshman year. Driving back home after finishing finals and heard it on the way. Thought it weird a song could ‘last’ 9 months on the radio.
Top 40 stations would typically play about 70% "heavy rotation" songs (usually songs that were rising in the Billboard Hot 100 chart) and then 20% would be for what they called "recurrents", songs that either exited or were falling from the chart but were still getting requested. The remaining 10% were for "oldies" or as a typical DJ would say, a "blast from the past" - such as a Rolling Stones or Beach Boys track.
If a song went to or near the top, it would take months to dislodge it from the playlist as it would spend up to six months in heavy rotation and maybe another 3-6 months in the recurrent playlist. For instance, I think I heard "Love Will Keep Us Together" (1975) pretty much every day for a year on my Top 40 station, which was WRKO-AM out of Boston. Ditto with "Listen to What The Man Said" by Wings.
I did not even discover FM until 1977. Until then, it was Top 40 on WRKO all the time.