Seeger recorded a 1974 album, Pete Seeger & Brother Kirk Visit Sesame Street, with Reverend Frederick Douglass Kirkpatrick, Big Bird, Oscar and the Kids. Around that time, he appeared in episode 0741, and sang "Put Your Finger in the Air", "Guantanamera", "Cottage in the Woods", and "Rollin' on the River".
In 1970 and 1971, Seeger's Sesame Street appearances set off a minor controversy, with a number of conservative parents writing angrily to the Children's Television Workshop with accusations that the show was promoting "a known and self-stated Communist," as one correspondent put it. The CTW defended the Seeger appearances and continued to book the singer on the program.
Seeger visited the series again in the 1980s, and appeared in the celebrity version of "Put Down the Duckie".
For his 90th birthday celebration, Oscar appeared and sang "Garbage" at The Clearwater Concert: Creating the Next Generation of Environmental Leaders, Seeger's benefit birthday concert. 
- ↑ Viewer correspondence in the Children’s Television Workshop archive, series I, box 17, folder 45, National Archive of Public Broadcasting, University of Maryland, College Park, Md.
- ↑ Pete Seeger Celebrates 90th With a Concert http://www.nytimes.com/2009/05/05/arts/music/05seeg.html?em