Back to the 1970s again

Last summer I went to Art in the Park in Windsor and discovered that this event preserves the attitudes and flavor of the 1970s to an almost scary extent. One of the key moments was when I spotted a man wearing a Dark Side of the Moon T-Shirt. Well this year I Went to Art in the Park and the first person I saw coming out of the park was that same guy or somebody else wearing a Dark Side of the Moon T-shirt. And one musician was playing the Crosby Stills and Nash song "Long Time Gone." Not quite a 1970s song but close enough. Thing is, this is the second time I've heard it sung live this month.