A very sad day for fans of the Beastie Boys, and for fans of the music, films and humanitarian/spiritual endeavors of Adam Yauch, a.k.a. MCA, a.k.a. Horatio Hornblower. You will be missed.
Rather than trying to crib off the no-doubt countless obituaries and tributes we'll see flooding our way soon, I'd rather just ask you to go back and listen to -
Check Your Head
Then I'd ask you to check some of the films released through Oscilloscope Pictures (which Yauch co-founded), among them -
Exit Through the Gift Shop
Gunnin' For That #1 Spot
Awesome; I Fuckin' Shot That!
Please also see the Criterion Collection release #100, the Beastie Boys Video Anthology (although, to be fair, many of the videos there were censored for explicit language).