Blow, who frequently collaborated with the DJ in the 1970s and 1980s, announced the sad news on Twitter.com on Wednesday.
In a message on the social media site, he wrote, "RIP to my DJ and friend Kool DJ AJ!!!!"
Ice T added, "RIP DJ AJ. Hip Hop Legend!"
And, in a post on Instagram.com, Grandmaster Flash adds, "I put this Dj in front of my biggest crowds in the 70s and he never let me down Kool Dj AJ he was my support Dj for more years than i can remember The Audobon Ballroom was the Triumph wowwwww Im (sic) gonna miss him".
Kool DJ AJ began making music in the 1970s and was featured on hit songs including Blow's AJ Scratch and Christmas Rappin' and Busy Bee's Chief Rocka.
He retired from music in 2010.
Details surrounding his age and cause of death have not been released.
In the 1980s, the streets of Compton were brutal. Five friends were brought together by...
Hip hop has always been more of a culture than just a genre of music....