It's so hard to believe that Pete Seeger, the folksinging hero to generations of Americans, just turned 90 on Sunday, May 3, 2009. One of my colleagues was lucky enough to get "scalper" tickets and attended the birthday bash at Madison Square Garden. She marveled at his posture, his agility on the stage, his banjo prowess and his ability to rouse the crowd to sing old-time favorites llike Amazing Grace, We Shall Overcome, and This Land is Your Land. The star-studded cast who honored him, included Joan Baez, Bela Fleck, Arlo Guthrie, Richie Havens, ...