Although Stephen Stills never became a Monkee, despite auditioning for the band and their kickass TV show (and then telling his buddy Peter Tork to join the band instead), he did wind up playing on a handful of Monkees sessions.
His guitar can even be heard on one of the band's most smokin' tunes, Tork's "Long Title: Do I Have to Do This All Over Again?” from the Head soundtrack album (1968).
But a lot of people don't know that Neil Young—Stills' Buffalo Springfield and CSNY bandmate—appears on more Monkees' tracks than Stills. You can hear his fretwork on "As We Go Along" and two outtakes, "Smile" and "That's What It's Like Loving You."
That said, the best of the bunch is "You and I," a little-known tune that appeared on the band's early 1969 album, Instant Replay. "You and I" is a killer song that got a bum deal. It wasn't released as a single, and because the Monkees' chart-topping days were pretty much behind them by 1969 (hey, it's true), Instant Replay didn't crack the top 10—or the top 30, for that matter.
Still, the Davy Jones-penned (with Bill Chadwick) track is super catchy, and Young's guitar playing is bold, powerful and overflowing with character and personality. His guitar is very clearly "in your face," sharing the spotlight with Jones' potent vocal. "You and I" is a clear-cut example of a massive hit that never was—but should've been.
By the way, Young's Monkees recording sessions took place just a few days after he left the Buffalo Springfield. You can never know too many useless facts, people.
Check out "You and I" (featuring Young) in the top clip and "Long Title: Do I Have to Do This All Over Again?” (featuring Stills, plus some super-slippery bass by Lance Wakely) in the middle clip.