JAY and Linkin Park have history ... they re-did the band's hit "Numb" back in 2004, so the mogul had reason to pick that song out to honor his good friend, who committed suicide a month ago.
You hear JAY at the VFest event fire an order to the crowd, "Let's show some love for Chester tonight!"
JAY is in the middle of a heavy touring schedule promoting his new album, 4:44.
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