JAY-Z and Eminem have joined the wider Hip Hop community in mourning the death of DJ Mark The 45 King, the accomplished producer and DJ behind “Hard Knock Life (Ghetto Anthem)” and “Stan,” among other Hip Hop classics.

The 45 King (real name Mark Howard James) passed away on Thursday morning (October 19), DJ Premier announced on social media that day. The news was later confirmed by his manager, Paul Martinez.

A cause of death has yet to be revealed, although Premo revealed in his heartfelt Instagram post that the Bronx-born producer — who had just celebrated his 62nd birthday on Monday (October 16) — was in hospital earlier this week.

After word of his death spread, JAY-Z’s longtime engineer Young Guru shared a message on Instagram from the Roc Nation mogul paying tribute to The 45 King.

“Thank you, Mark. Your instrumentals, namely ‘The 900 Number,’ were more memorable than our whole albums,” Hov wrote. “You gave me a canvas to have a conversation with the world!! You changed my life. Even when the life is short, the art is long!!”

In a tweet of his own, Eminem said: “Legends are never over. #RIP Mark Howard James aka The 45 King … I’m 4ever grateful!!!” His post was accompanied by a video of the late producer talking about the making of “Stan.”

Named for his ability to make beats using obscure 45 RPM records, DJ Mark The 45 King enjoyed breakout success with his 1987 song “The 900 Number,” as well as his work on Queen Latifah’s 1989 debut All Hail the Queen. The pair were groupmates in the Flavor Unit alongside Apache, Lakim Shabazz and Chill Rob G.

The 45 King’s career continued to flourish in the late ’80s and early ’90s thanks to collaborations with the likes of Gang Starr, Eric B. & Rakim, Salt-N-Pepa, Madonna and MC Lyte, while solo releases such as Straight Out Da Crate and The Lost Breakbeats series were some of the first instrumental projects in Hip Hop.

Two of his biggest production credits came towards the turn of the millennium in JAY-Z’s “Hard Knock Life (Ghetto Anthem)” and Eminem’s “Stan,” both of which enjoyed huge commercial success and helped solidify the two rappers as global superstars.

The former was especially pivotal for Hov, becoming his highest-charting single at the time (No. 15 on the Billboard Hot 100) while earning him a platinum plaque and a Grammy nomination for Best Rap Solo Performance.

“‘Hard Knock Life’ opened the door for everything Jay has. Everything he is known for, that was the door opener right there,” Kid Capri told Grantland in a 2014 oral history of the song.

Tributes to The 45 King also poured in from Diamond D, Kid Capri, The Alchemist, A-Trak, Roc-A-Fella Records co-founder Kareem “Biggs” Burke and more. Check them out below.