Following Mac Miller’s extremely untimely death this past September, an all-star cast of musicians came together on Halloween to celebrate the young rapper’s life. Dubbed Mac Miller: A Celebration Of Life, the tribute featured Action Bronson, Anderson .Paak, Chance The Rapper, Domo Genesis, Dyan Reynolds, Earl Sweatshirt, J.I.D, John Mayer, Miguel, Njomza, Schoolboy Q, SZA, Thundercat, Travis Scott, Ty Dolla $ign, Vince Staples, and more at Los Angeles’ Greek Theatre.A highlight of the evening was John Mayer’s appearance, as the guitarist first worked through a cover of Mac Millers’ “Small Worlds”, which Mayer is featured on in the recording on Swimming. Mayer then worked through a take on his own “Gravity”, before joining bassist extraordinaire Thundercat for a take on his original “Them Changes”. Watch video of John Mayer’s celebration of Mac Miller below:John Mayer – “Small Worlds”[Video: Something Like Mayer]John Mayer w/ Thundercat – “Them Changes”[Video: Something Like Mayer]John Mayer – “Gravity”[Video: Something Like Mayer]Mac Miller: A Celebration Of Life – Full Show[Video: Jacob Yanosick]Following Miller’s death, John Mayer posted a very heartfelt message on his Instagram about the young artist. Read his sentiments below:This was going to be Mac Miller’s year. He made a quantum leap in his music. That’s incredibly hard to do, to evolve and get better and more focused while your career is already underway. You don’t get there without a lot of work, and Mac had put the work in. I didn’t expect to play on his album the day he played some songs for me at his house, but when I heard “Small Worlds,” I gave it a short, chirpy little “yup,” which is the highest praise I can give a track. It means we don’t need to say another word, it’s going down. I grabbed the nearest guitar in the room and within a couple of hours we had finished a tune that made me so incredibly happy to have a part in, not to mention we established a nice little friendship. He was so funny I just kind of stopped typing “LOL” back in our texts. Mac was, to me, on permanent LOL status. I gave him whatever guidance I thought I had the right to, having been through the press ringer in the past and wanting him to understand that none of that noise could ever really take a bite out of the music he was about to put out.The last time I saw him, he was playing Hotel Cafe’ in Los Angeles for a crowd of 100 people. He was nervous, and honest about it with the audience. I thought that was so endearing, especially seeing as he would go on to play one of the best sets I’d seen in a very long time. His band was unreal. You gotta know that if you weren’t familiar with Mac Miller, you were about to be, whether you would have seen him at a festival, or a friend was going to catch a show and tell everyone they knew about it (like I did.) Mac put in the work. He made his best album and formed the band that was weeks away from becoming a breakout live sensation. Believe me when I say that. I send my love and support to everyone who knew him better, because what relative little I did, I just adored.