Joni Mitchell sings at star-studded Gershwin Prize concert

Joni Mitchell performed for the crowd at a star-studded concert held in her honour on Wednesday.

On Wednesday night, the Big Yellow Taxi singer was presented with the U.S. Library of Congress' Gershwin Prize for Popular Song at an event staged in Washington, D.C.

After accepting the prestigious honour, Joni thanked her friends and peers for attending, with the likes of Annie Lennox, Cyndi Lauper, Graham Nash, Diana Krall, James Taylor, and Brandi Carlile all in the crowd.

"So many people I care about are here tonight," the 79-year-old said, according to USA Today. "New friends, old friends. It's kind of thrilling."

At the end of the evening, Joni also stunned the audience with a rendition of George Gershwin's Summertime, which he originally composed in 1934 for the opera Porgy and Bess.

The star has made few public appearances since suffering a brain aneurysm rupture in March 2015.

Prior to the event, Scottish singer-songwriter Annie gushed over Joni's influence on her career.

"A guide to me about how a woman could be a singer-songwriter," she praised.

The Gershwin Prize for Popular Song is described as America's "highest award for influence, impact and achievement in popular music".

Previous recipients include Paul Simon, Stevie Wonder, Paul McCartney, Carole King, Billy Joel, Willie Nelson, Smokey Robinson, Tony Bennett, Emilio and Gloria Estefan, Garth Brooks, and Lionel Richie.

The concert is set to air in the U.S. via PBS on 31 March.