Classic basically means a track still played 10, 15 years after its initial release.
Britney has none (her recurrent airplay HAHAHA)
Beyonce has Listen, Irreplaceable.
CHRISTinabigjug has Beautiful, What A Girl Wants & Genie.
Recurrent airplay doesn't mean a song is a classic There is so much vile trash that gets endlessly played on AC and HAC stations that no one ever liked. And you're talking only about the US. None are here for local receipts.
Poor Miley, she infected her tongue by licking everything and anything in sight to the point where it needs to be snipped off and she still didn't own 2013.
Actually if Single Ladies is considered Bernie's 2nd classic, we might as well list Slave as one, considering both are mostly famous for their videos and in Slave's case, also an iconic performance.
If Blackout is a classic because it's a fan and critic fave, then this means 4 is a classic.
Classic is something that has resonated outside of pop culture/consciousness something which neither Blackout nor 4 have done. BOMT or Oops maybe because the blockbuster surrounding Knee as Queen of Teen at that time
CIL is an artificial classic. It's the product of the media campaign to paint Pepcé as some kind of legendary artist, even though she has no classic hits. So they had to jump on her one global hit and elevate it.
Everyone knows how much I love CIL, I was really pissed at the time that it didn't smash worldwide.