[M]y dad cannot understand why an oldies station would play Bill Haley or Pat Boone instead of Chuck Berry, Jerry Lee Lewis or Fats Domino. That, of course, was back when oldies stations played music from the 1950s, which they don’t anymore.
Short answer: Program directors as we know them today were not around in the 1950s and have no sense of history. They do, however, have access to historical charts, and they know that Chuck Berry never had a #1 song in Billboard until 1972, with the loathsome “My Ding-a-Ling.” Fats? Peaked at #2 (“Blueberry Hill”). The Killer? #2 (“Great Balls of Fire”). Meanwhile, anyone who had a #1 song gets preference. Bill Haley had one. Pat Boone had six, fercryingoutloud.
People who actually listen to the music, as distinguished from people who merely select items from a database, generally pay little or no attention to the charts. The poster child for this phenomenon might be “I Put a Spell On You,” which failed to chart at all, either pop or R&B, for singer/songwriter Screamin’ Jay Hawkins in 1956. Yet everyone knows the song, because it’s been covered by everyone from Nina Simone to Creedence to Zooey Deschanel, the latter in her capacity as half of She & Him.
And radio stations don’t seem to have record libraries anymore: instead, they have hard drives full of compressed tracks, a couple hundred of which might be in actual rotation. I have occasionally referred to my work box as the Radio Station from Hell, ostensibly because at least once every hour it’s guaranteed to play a song you hate. The actual motivation is this: inasmuch as it contains something like 6700 tracks, it takes about three months to cycle through the lot, and any contemporary radio program director who proposed something like that would be charged with heresy and summarily dispatched to Sheol within three hours. This is not the circumstance that led Morrissey to call for the hanging of the DJ, but it might as well have been.