Folk music legend Pete Seeger joined Occupy Wall Street demonstrators in 2011. (The Associated Press)

For the Seeger historians, the two previously unavailable songs are “Al Smith Holds the Bottle” and “I Had a Dream.” Included in the concert were “Goodnight Irene,” “Where Have All the Flowers Gone?” and “Bourgeois Blues.”

Seeger will celebrate his 93rd birthday on May 3.