SXSW performance

Willie Nelson Gives Surprise SXSW Performance at Ray Benson's Birthday Party

Willie Nelson delighted the audience at Ray Benson's 66th birthday bash on Tuesday night during SXSW in Austin.

The country legend capped off the show with a new song and a quick set of his classics, including "Whiskey River," "On The Road Again," and more.

Nelson also joined Benson and the Avett Brothers for a rendition of Townes Van Zandt's "Pancho & Lefty." See their SXSW performance in this clip from Austin360.

Benson's annual birthday bash is always quite the event. Held in the backyard of Austin advertising firm GDS&M, the party always has a great lineup and a few surprise performances. Last year, George Strait showed up to play a few songs.

READ MORE: The Country and Americana Fan's Guide to SXSW 2017

This year's party featured performances by the Avett Brothers, Wade Bowen, Randy Rogers, Carolyn Wonderland, Charlie Sexton and Brennen Leigh, who will perform tonight (March 15) at Wide Open Country's showcase.

Now Watch: John Moreland's 2016 SXSW Performance