In the depths of YouTube lurk a pair of grainy TV commercials from the 1970s that tell the story of the labor movement’s efforts to remain culturally relevant at the onset of an employer counteroffensive.

The first shows a multiracial group of women workers from the International Ladies’ Garment Workers’ Union (ILGWU) singing a tune that seems to echo from generations of factory workers past: “Look for the union label! / When you are buying / A coat, dress, or blouse! / Remember somewhere / Our union’s sewing / Our wages going / To feed the kids / And run the house!”

The public service announcement and its jingle were so ubiquitous at the time that they were widely parodied everywhere from Saturday Night Live — with Bill Murray and Gilda Radner of the American Dope Growers’ Union singing, “Look for the union label!” — to contemporary sitcoms’ plots about unionization on series such as WKRP in Cincinnati. Later generations might have come to know the ad from ’90s sitcom Boy Meets World, or its appearance during a commercial break on one of the only extant recorded copies of the infamous 1978 Star Wars Holiday Special.