The 69-year-old singer paid tribute to his late friend -- who died on Christmas Day 2016 -- on his Beats 1 radio show, Rocket Hour, with a series of Michael's classic songs following a heartfelt memorial.
"Not only was he a good friend, but he was probably one of the most brilliant songwriters this country has ever produced, and certainly one of the best vocalists ever ... one of the best in the world," John remembered, noting that Michael's gift of song never ceased to amaze him.
"I remember sitting in the car just off of Hyde Park, listening to a cassette of 'Wake Me Up Before You Go-Go,'" the singer continued. "I said, 'George, that's the nearest record I've heard to a Motown record for years and years."
Of course, musicality isn't the only thing Michael was known for.
"I just wanna remember him for his wonderful music and his kindness ... Without any publicity, I've seen him being so kind to so many people," John shared. "I'll miss him so much for his music, but more than anything, for his humanity."
Listen to John's emotional words about his friend below.