Having previously performed "XO" live and acoustic at a show in Australia, Mayer gave his cover the proper recording treatment and released it Thursday. Though "Drunk in Love" seems to be the breakout hit from Beyoncé's surprise self-titled album and celebrity cover magnet between remixes from M.I.A. and attempts to do the song justice by Allen and Ed Sheeran, "XO" is next in line. Haim recently took to the BBC Radio 1 Live Lounge to try their hands at the love song; Mayer's version is way more stripped-down. Listen to his cut of "XO" above and try not to think of running through the walls of your high school when you do it.