Stars unite to celebrate Willie Nelson's 90th birthday with music and love.

A sold-out crowd gathered at the Hollywood Bowl to celebrate Willie Nelson's 90th birthday with a two-night tribute concert featuring over 50 artists performing about 75 songs. Saturday's show included performances by the Chicks, the Lumineers, Ziggy Marley, Miranda Lambert, Beck, Chris Stapleton, Tom Jones, Norah Jones, Bob Weir, Jack Johnson, Margo Price, Kris Kristofferson, George Strait, Neil Young, and Snoop Dogg. The concert paid tribute to Nelson's songwriting mastery and enduring appeal, with some performers playing deep cuts and others playing his biggest hits. The event also featured surprise appearances by Keith Richards and Justin Timberlake.