When Chris Stapleton turns 40 on Sunday (April 15), he'll have plenty to celebrate: He'll be getting ready to have four kids in his family instead of two; he'll have three No. 1 records under his belt; and depending on how the 2018 ACM Awards go on the night of his big 4-0, he could walk away with up to five awards before his birthday is over!

Throughout Stapleton's 17-year career, he's collaborated with countless artists as a songwriter and more than a few as a performer in his own right, bringing a soulful, gritty and downright beautiful sound to traditional country music. Artists from all genres have been known to pine for a spot singing alongside him; in fact, Justin Timberlake has (jokingly?) admitted he "fangirled" and "stalked" Stapleton after hearing "Fire Away" for the first time.

In honor of Stapleton's 40th birthday and the amazing artistry and music he has gifted to the world, let's take a walk down memory lane. Below are five of The Boot's all-time favorite collaborations from Stapleton.

  • Brent Cobb

    A live collaboration between Stapleton and Cobb was practically a given during Stapleton's 2017 All-American Road Show, for which Cobb was an opener. But what fans might not have expected was that they would duet on a classic rock song.

    On the final night of Stapleton's tour, Cobb joined him onstage to pay tribute to late, great AC/DC guitarist Malcolm Young. The duo performed a unique cover of the band's classic song "You Shook Me All Night Long," slowing down the hard-rock anthem into more of a country love ballad. From the drawling chorus to a mid-song guitar shred, it was perfect.

  • Morgane Stapleton

    Stapleton never really takes the stage without his wife, and it's for good reason: Anytime the two sing together, it's pure magic. Case in point: when he and Morgane collaborated for Dave Cobb's Southern Family compilation album and turned a simple lullaby, "You Are My Sunshine," into a epic, bluesy love song. The song has since become a regular in Stapleton's setlist, garnering practical pandemonium every time the two sing it together onstage. The song is also super special to the couple; Chris even has its title engraved on the inside of his wedding ring!

  • Justin Timberlake

    Fans at the 2017 Pilgrimage Festival, which took place outside of Nashville, were in for quite a treat when Stapleton and his wife hopped onstage during Timberlake's headlining set. Of course, now we know it was foreshadowing their stellar duet, "Say Something," on Timberlake's 2018 album Man of the Woods, and the announcement that Stapleton will be headlining the fest in 2018, but in September, it was a definite surprise! Timberlake and the Stapletons -- who, of course, are also responsible for one of the greatest moments in recent CMA Awards history -- performed "Tennessee Whiskey," "Fire Away" and "Sometimes I Cry," with Timberlake practically falling all over himself in awe of Stapleton ... and rightly so!

  • Miranda Lambert

    "Fire Away" is an opus in itself, but when Lambert took the stage during Stapleton's 2017 tour stop in Buffalo, N.Y., she added a whole new level of awesome to the track. Surprising fans by casually walking onstage at the start of the song, Lambert let Stapleton stay in the driver's seat for most of the tune, adding harmonies alongside his wife, Morgane. But near the end, the Stapletons stepped back from their mics and let her take center stage as she roared through the song's last bars. It was powerful and perfect and everything you would want a collaboration between Lambert and Stapleton to be ... just like their turn on "My Girl!"

  • Lady Antebellum

    Stapleton teamed up with Lady A at the 2014 CMT Artists of the Year event to honor another country singer, Luke Bryan. When Bryan had to step away from the show after the death of his brother-in-law, Stapleton, Dave Haywood, Charles Kelley and Hillary Scott used the void to pay tribute to the singer and his family with a moving rendition of "Drink a Beer." The song, which was a 2013 hit for Bryan, was written by Stapleton and Jim Beavers.