I always assumed that when KHJ-FM in 1972 decided to become KRTH (K-Earth), the new call letters were inspired by the first Earth Day, which took place in 1970, and the popularity of Earth Shoes (with the thick soles and thin heels), which went on sale in 1970. In response to semoochie, I'm guessing that, thirty years from now, when classic hits stations are playing music from the early 2000s, there won't be many songs from 2002-06, when hip-hop was so dominant. But I could be wrong---perhaps listeners in 2043 will want to hear Nelly, Eminem, Missy Elliott, Chingy, 50 Cent, Ja Rule, The Game, Ludacris, Ciara, and Kanye West.
Michael, 1964 through 1990 is a 27-year-span, not 26. You have to take all those years inclusive, not just subtract 1964 frrom 1990. I know you think I don't understand much about formats and playlists...but I do know my 'rithmetic.But the issue will soon be moot because I think KRTH will soon be 1970s-80s-90s the same as KOLA.
Your assumption about the name is correct, but the thought was that the Earth Day/Last Whole Earth Catalog thing resonated with an album audience.
You're still assuming that the station will be playing 40 year old records in 2043. That would be a mistake. You want 40-year-old listeners (which then would be people who are 10 this year), not 40-year-old music (with a handful of extreme exceptions).
As for 27 versus 26, fine...that's 675 titles, which is still less 175 fewer tracks than KRTH plays now.