Led Zeppelin - San Francisco (Be Sure to Wear Flowers in Your Hair)
http://www.youtube.com/watch?v=z19xIhUNgxI

"San Francisco (Be Sure to Wear Flowers in Your Hair)" is a song, written by John Phillips of The Mamas & the Papas, and sung by Scott McKenzie. It was released in 1967 ("Summer of Love"), and became a cultural icon of the 1960s counterculture of Haight-Ashbury, San Francisco.
In Central Europe, young people adopted "San Francisco" as an anthem for freedom, and it was widely played during Czechoslovakia's 1968 Prague Spring uprising against Soviet rule.
"San Francisco" was extensively used by Led Zeppelin in their live performances, during their Dazed and Confused era, and is featured in the concert film, The Song Remains the Same.