Prog used to be poison to alt-rock types. In fact, hatred of bands like ELP and Yes were one of things that helped give birth to punk rock in the 1970s.
Those attitudes have mellowed in many quarters to the point where there are a number of well-regarded alt-rock bands that have quite a bit of of prog in their DNA. (I'm looking at you, Coheed and Cambria.)
Now that it's almost safe to say prog is cool again, it might be worth digging into its history. Here's a fine article on the subject from Slate.
The death of real rock ‘n’ roll began one morning in 1964, at the Organ Center in the southern England city of Portsmouth. Keith Emerson, 19, had 200 pounds to spend on a keyboard. He had options. But he got distracted by something bigger, more beautiful, and beyond his means.
“There it was,” he remembers in his autobiography, “resplendent in beautiful shining mahogany—the Hammond L 100 electric organ. I played it.” He heard the warm tones, engineered to sound like they came from pipes, but with distinctive warm hums. “That was the sound.”
Emerson had noodled around with the Hammond before. The L 100, rolled out in 1961, imitated the sound of a church organ by placing 96 metal tonewheels in front of 96 electromagnetic pick-ups. The tonewheels rotated, charging the pick-ups, generating the sound. Two keyboards shared space with nine “drawbars”—move the bars, change the sound of your notes. Jazz musicians used this, as did (somewhat less inspirationally) the nice old ladies who played during the dull sections of ballgames.
Read the rest--and I highly encourage it--here.