The Triangle Bar was at 1822 Riverside on the West Bank, at the confluence of Riverside, 19th Ave. So., and 4th Street So. It’s said to be the oldest bar in Minneapolis, dating back to 1887, although Hennepin County dates the building to 1901. See a comprehensive history here. In 1941 Frank Ojilie was the proprietor and “swamper.”
It began hosting live music in 1964, with Spider John Koerner the first paid musician. Koerner, Ray, and Glover were frequent performers. In mid-1971 it got a license to host groups.
It became the Ole Piper Inn in 1976, and closed down in about 1990. The building is now listed as residential.