so many BOSs to choose from, but "If I Were Your Woman", you'd have no other woman, by an obviously pre-Mormon Gladys, is as powerful today as it was the first time I heard it at age 15.
BOS2 "Rose Garden", as perfect a country-pop single as the '70s produced.
and of course BOS3 Babs-does-Laura Nyro. I've probably said this before, but in 1971 I thought of Streisand as "old", someone my parents listened to (I figured she must be in her 40s at least). So finding out she was 29, as she recorded her first LP of contempo songwriters -- people her own age, more-or-less... was a revelation.