Help me identify this track, plz

Ok. This is something I heard as a kid. It was on one of my dad’s home made tapes (audio cassette, you know) together with ELO’s “Rain is Falling” (from “Time”), “Ai no corrica” (not sure what version) and Sheena Easton’s “9 to 5“. So the tape is from around 1980/81. It’s a five-and-a-half minute [...]