If you chose the Beatles, obviously there's more of a range of songs you could have picked so you better pick one of the more memorable ones.
If you chose The Spice Girls, sure there are a few choices, but pick the one that is superior to the others.
I never said they had to have 1 song that is actually memorable. Can't blame them for having multiple huge hits.
I'll try to make the next round as clear as possible though.
