Huge, huge loss to the jazz world. He was an innovator on two fronts, bringing jazz to the college campus (and thus, the younger crowd) and his quartet's innovative use of the time signature. Everything (mostly) was written in 3/4 or 4/4 until the mid 50s, when Brubeck began experimenting with 5/4, 9/8 and 11/4. It all came together with "Take Five."
Watch this clip from the pre-PBS show "Jazz Casual." Brubeck does a great job explaining to the host, the columnist Ralph Gleason, about using different time signatures.
My g/f surprised me tickets to see him two years ago, but he was coming off an illness and couldn't perform, so his son, Darius, sat in instead. It was a mirror image, both in playing and in looks.
Very sad today.