Willie Nelson and Billy Joe Shaver stopped by The Late Show with David Letterman last night, bringing with them more than 95 combined years of renegade attitude and trend-bucking country music. Backed by a lean band cobbled together from Shaver and Nelson’s touring outfits, included harmonica wiz Mickey Raphael, the two traded verses, harmonies and grunts on “Hard to Be an Outlaw,” a track that appeared on both of their solo albums — Shaver’s Long in the Tooth and Nelson’s Band of Brothers — earlier this year. 

Shaver penned the song himself, turning his back on country’s longstanding tradition of co-writing with other musicians. Inspired by a series of text messages exchanged with Nelson — yes, the two text each other on a regular basis — “Hard to Be an Outlaw” is a dark, deliberate anthem for the left-of-center legends whose music stands in stark contrast to the glamor and glitz of contemporary country radio. Shaver, who famously shot a man in the face during a barroom disagreement seven years ago, focuses his crosshairs on a different kind of enemy: the modern-day country stars who “get too far off the ground/Singing ’bout the backroads they never have been down.” 

“It’s not harsh enough, I don’t guess,” he told Rolling Stone Country back in May 2014, three months before Long in the Tooth‘s release. 

Indeed, it’s hard to be an outlaw… but it’s hard to be a senior citizen, too. Shaver and Nelson — 75 and 81 years old, respectively — aren’t as spry as they used to be, and the Letterman performance relied as much on grit and swagger as actual execution. Still, broadcast across the same prime-time airwaves that showed the lackluster American Country Countdown Awards earlier this week, the pair’s performance was a welcome reminder that raw, real music doesn’t need confetti cannons and smoke machines to pack a punch.