Complex sentence: In the mid- 1960s through to the late 1970s, the Perth County Conspiracy would play nightly at Harry Finlay's Black Swan Coffee House in Stratford, Ontario, usually following the evening performances at the Stratford Shakespearean Festival Theatre.
Split into simpler sentences: In the mid- 1960s through to the late 1970s, the Perth County Conspiracy would play nightly at the Black Swan Coffee House in Stratford, Ontario which was run by Harry Finlay. The performances usually followed after the evening performances at the Stratford Shakespearean Festival Theatre.