Guru of Gang Starr

Guru, the pioneering hip-hop legend who united jazz and hip-hop as a solo artist and half of the influential duo Gang Starr, has died. He was 43.

Guru, whose real name was Keith Elam, died Monday after a battle with cancer, his producer, Solar, told MTV. Guru was hospitalized late February after suffering cardiac arrest and was briefly in a coma.

During his final days, Guru penned a farewell letter to his fans to be released upon his death, Solar said.

"I, Guru, am writing this letter to my fans, friends and loved ones around the world. I have had a long battle with cancer and have succumbed to the disease," the letter read. "I have suffered with this illness for over a year. I have exhausted all medical options. I have a non-profit organization called Each One Counts dedicated to carrying on my charitable work on behalf of abused and disadvantaged children from around the world and also to educate and research a cure for this terrible disease that took my life. I write this with tears in my eyes, not of sorrow but of joy for what a wonderful life I have enjoyed and how many great people I have had the pleasure of meeting." (Read the whole letter here.)

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Those mourning Guru included Ice-T, who tweeted Monday that he was "paralyzed with sorrow."

"Guru... Rest In Peace O.G." he added. "I miss you."

Guru first found fame in the late '80s when he partnered with DJ Premier to form Gang Starr, releasing such classic albums as No More Mr. Nice Guy and Step in the Arena. Though Guru was rooted in Boston and Premier in Houston, their sound came to define the dense New York underground rap sound — one characterized by jazz loops and complex rhymes.

In 1993, Guru released his first solo album, Jazzmatazz Vol. 1, the first of his four-volume Jazzmatazz series. The disc featured collaborations with such notable jazz musicians as Donald Byrd and Roy Ayers.

Guru reteamed with DJ Premier to release three more Gang Starr albums, the last of which, The Ownerz, hit shelves in 2003. But the two had a falling out, and Guru wrote in his letter that he didn't want Premier to participate in any tributes following his death.

In recent years, Guru worked with Solar, who produced Guru's final Jazzmatazz installment and two other solo albums.

Guru is survived by a son, KC.