From the Seattle Summer Events Guide:

Ask the classically trained, hard-rocking cellists of Portland Cello Project to play their cover of Kanye West’s “All of the Lights” at Two Union Square during this Out to Lunch set. You won’t regret it.

The outdoor concert starts at noon and goes till 1, 1:30.

Updated 10:30am. If you like what you see this afternoon, Portland Cello Project is also playing the Triple Door with Scott MacIntyre (American Idol, Season 8) on August 29. Tickets ($20-$25) are available at thetripledoor.net.