  I saw Yes , or was it some contemporary offshoot, in San Francisco 20 years ago. I remember the opening act, some guy in a black body suit who juggled lights, better than I remember the music. I fell asleep during the concert. I fall asleep during most concerts. Really loud, ear drum shattering rock music has a way of lulling me to sleep. It must sound like my mothers heart beat. Not that shed ever admit it. I slept through Peter Gabriel, Talking Heads, Blue Oyster Cult, Grateful Dead , to name a few. I was a real wild teenager. Sleepy, tho. 
