More than one.

I'd been listening to Peter, Paul and Mary, the Dubliners, and some bluegrass programs on the radio through the 70s. One day I heard an Irish music group with whistles, bouzouki, guitar, and pipes on KPFK around 1981 when I was fifteen. I don't remember the group, even, but the music was so different from what I'd heard previously that I felt as if I was having a religious experience. I couldn't get to sleep that night; my whole life changed from that moment.

Some months later I heard a Canadian singer being introduced on the radio and they played Stan rogers' "Northwest Passage". Wham! That was almost like a physical blow; I had to get that. Unfortunately, I lived in a small town, and I didn't think I'd come by it any time soon.

A few years later, I moved to the San Francisco bay area, and someone told me about a record store that sold folk music and other rare stuff, and I went in and asked if they had any Stan Rogers.   "Which one?" So there's where I got Northwest passage. :D

Teresa