40 years ago U2 tore it up at the Red Rocks Amphitheatre, Colorado. The venue has issued its own statement to mark this anniversary: “Even with inclement weather, some 4,400 persistent ticket holders shared a powerful spiritual experience captured by one of the music industry’s most remarkable videos, “Sunday Bloody Sunday.” The video caught singer Bono marching with a white flag across a stage lit by flaming torches and bonfires. The concert and subsequent live concert video put U2, and Red Roc