The following is just 1 man's opinion, who happened to grow up at the beginning of what we call R&R.
I couldn't separate 2 as far as their greatness, for different reasons really. So I had to edit the thread to include more than 1 choice. I could have left it as 1 choice, The Beatles, but that just seemed too obvious, and possibly simpleminded.
I grew up through the Beatles, and unless you did, you could never have the complete feel and understanding of their entire greatness. They had to be chosen for their originality, creativeness, variety, style, and sound. They defined a culture, influenced a generation, and shaped a world.
Zeppelin was simply the best in-your-face rock musicians ever, individually and otherwise. They are the Beatles in different form and substance. R&R stripped away of pretense and glamour, perfected to the extreme.
The Beatles united the world in their music, all ages and styles. Through them, R&R became an art form that all could appreciate and emulate forever.
Zeppelin took us at light speed into rock's ultimate dimension, quickly reaching the boundaries of the observable musical universe. Rock's ultimate journey, beginning in the 50's, reached its pinnacle in the 70's with Zeppelin. Since LED Zeppelin, rock has become what seems like nothing more than one long cover song.
