I'm almost certain that most "music fans" could not even name all the Beatles.

Let's just assume that "music fans" are limited to the populations of the United States and the United Kingdom, except the occasional person who just doesn't like music - and I can't think of another definition that better favors knowledge of the Beatles. I think if you told random people that John, Paul, George, and Ringo comprised the Beatles, then that would sound correct and familiar to most people. But I think if you prompted random people to name all the Beatles, then I don't think more than 50 percent of them could do it.

It wouldn't surprise me, however, if once upon a time a majority of those people could do it. But certainly not today.