There is often a lag. By birth, Lou Reed and Bob Dylan are pre-boomers (b. 1942 and 1941), Leonard Cohen even earlier (1934), as are the British Invasion groups of the 1960's, while R.E.M.--typically considered a 90's band--is solid boomer (1956, 58, 60).

I hadn't heard that Cult song before, and yes, I would probably have said it was late 90's.

Often people who are out of step during their lifetime are later considered ahead of their time (Sun Ra b. 1914; Frank Zappa, Captain Beefheart....). And sometimes the fortune of a particular group or style vacillate back and forth (Steely Dan--are they in or out now, I've lost track).

My own candidate for a timeless AND historically significant song that is both of its time and has the potential to be surprising even today would be "Eight Miles High" by the Byrds (only drummer Michael Clarke is a Boomer). But I'm giving away my age (and my taste) there.