John Mayer has shared a heartfelt tribute to the late Mac Miller, whom he dubbed as a ''sensational'' musician.

The 'Donald Trump' rapper tragically passed away at the age of 26 of Friday (07.09.18) after suffering an apparent overdose, and fellow musician John Mayer has taken to Instagram to praise the star's musical talent.

Posting a professional picture of Mac on social media, John wrote: ''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.

''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.

''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. 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.''

John, 40, is just one of the many starts to reach out following the news of Mac's passing, including his former girlfriend Ariana Grande - whom he dated for two years until earlier this year when they split - who posted a simple black and white photo of Mac without a caption.

Both Sir Elton John and fellow rapper G-Eazy have paid tribute to the star at their concerts this weekend.