Pete Seeger turns 90 next week. It's hard to imagine American music - or even America - without him.

As a young adventurer, Seeger rode the rails and went hoboing with Woody Guthrie, who taught him the power of song to unite a movement. Seeger served in World War II and returned to sing on a No. 1 hit record, The Weavers' cover of Leadbelly's "Goodnight, Irene." He was a star and was offered a national TV show of his own - and then the roof fell in.

Called before the House Un-American Activities Committee witch trials in 1955, Seeger refused to cooperate. He did not deny his former Communist Party membership; he simply denied that there was anything illegal or unconstitutional about it. So he was found in contempt, sentenced to prison and effectively blacklisted. He would not appear on national television again until 1967, singing an anti-war song on "The Smothers Brothers Comedy Hour."

HUAC guessed wrong when they pushed Seeger into commercial purgatory. He did not give up; he simply turned his career and his evangel to the next generation. Through the rest of the '50s, he performed mostly for students, singing school-time concerts and college gigs.

I know; I was there.

One day in the late '50s, my elementary school in western Massachusetts piled into yellow buses and rode to Springfield to see a folksinger.

The name of that tall, thin man with the long-neck banjo and guitar didn't stick in my head, but to this day I remember some of the songs he played - not just the titles, but the tunes and lyrics. The kids in the Springfield Auditorium sang along shrilly to "Sinner Man" and sat rapt as his 12-string tolled a dirge for lost Welsh miners in "Bells of Rhymney."

It was only years later, during the folk music revival of the '60s that I saw his face again and put his name with the music. Seeger would have had it no other way; for him the music was the message.

When he sang to students, he introduced us to tales of labor strife and racial oppression omitted from our history classes back then. In concerts all across the country, he planted impressionable minds with the seeds of the social activism of the '60s. You get the feeling that's not what the red-baiters had in mind when they tried to silence him.

The '50s were the high-water mark for union membership in America, so Seeger adapted Guthrie's use of labor organizing songs to the fight against racial segregation and the Vietnam War. He wrote or co-authored such anthems as "We Shall Overcome," "Where Have All the Flowers Gone," "If I Had a Hammer," "Turn, Turn, Turn," and "Guantanamera" - songs with such staying power, it's as if they'd always been here ... like Pete himself.

As documented in the video documentary "Pete Seeger: The Power of Song," virtually every folksinger of the '60s - from Peter, Paul and Mary to Joan Baez to Bob Dylan - pays tribute to Seeger's model of idealism, personal courage and above all, devotion to music.

Songs gave voice to forces for peace and civil rights in the '60s, and Seeger himself did overcome, just as his song proclaimed. To see him singing for the new president, emanating his optimism and good cheer that never flagged, made me think of all that's best about my country.

When he stood on the steps of the Lincoln Memorial on the weekend of the Obama inauguration to lead the throng in Guthrie's "This Land is Your Land," it was America that had come full circle. Pete had stayed the course.

THIS IS THE OPINION OF MILTON MOORE.