12-12-12 Concert for Sandy Relief: Musicians React on Twitter

Mick Jagger belts a Rolling Stones hit during the 12-12-12 Concert at Madison Square Garden

Thousands of fans packed into New York City's Madison Square Garden Wednesday night at the 12-12-12 Concert for Sandy Relief, where an A-list line-up of stars rotated on and off the stage for a solid five hours. The concert, broadcast online and on televisions across the world, was watched by fans and other musicians alike.

Sandy Concert Rocks NYC | PHOTOS: 12-12-12 Concert

See what celebrities -- from performers Mick Jagger and Bon Jovi to bystanders Sara Bareilles and Josh Groban -- had to say about the charity concert and its many top-notch performers.