In September, the Red Rocks Amphitheatre will host the aptly titled Monolith Festival. Monolith promises multiple stages over two days, on September 14 and 15 with over 50 bands in the final line-up. Confirmed artists this far include: The Flaming Lips, CAKE, The Decemberists, Kings of Leon, Spoon, Clap Your Hands Say Yeah, Brian Jonestown Massacre and Das EFX. Tickets will go on sale on Saturday June 2, with both single day and two-day passes available.