[Epona]

I agree that the Beatles have to be one of the greatest (if not the greatest) band of all time.

They may not have been the most innovative group of the time, either musically or lyrically, but they popularised a certain style of music that has influenced pop and chart music ever since.

In terms of influencing the direction of popular music, there are plenty of artists that should be considered.

Carl Perkins - one of the first artists to popularise black music amongst a white audience through rockabilly - writer of Blue Suede Shoes, and several songs performed by the Beatles. Didn't achieve overwhelming success as a performer in his own right, but played an important role in the development of rock and roll.

Elvis Presley - again in his early years popularised black music amongst white youth. Don't underestimate the importance of that in modern music! At the time, black artists simply could not get played on white radio stations, and were largely unheard of. Without Presley, the audience for black music would have been far smaller, and would maybe not have the same impact it has today, or would have taken longer to be acheived.

I'll try to think of some more later.