How Broad Can Prog Be?

This past weekend, the University of Pennsylvania's radio station played a 24 hour Prog marathon. Everything was from between 1969 and 1979. I'd heard a great deal of it, but some stuff struck me as being off. There was music that I myself would describe as country, free jazz, and even pop without being particularly prog. Is there any semi-objective standard?

For example, drum Machines- Progressive Rock is all about technicality. Drum machines were available as early as the mid-70's in a primitive, extra noticeable form. Can we count music that does this sort of "lazy coping out" as Prog Rock? Or those Short Songs- Prog can be short. But can prog be short with a two verse, chorus, bridge, verse, chorus structure? Pop and Punk follow such patterns, and these things are what made Prog fade away. Therefore, isn't it a litlle bit contradictory to call this prog?

Progressive Rock is more than just a lable. It has a feel. Progressive rock can take the form of a jazz work, an electronic droning, a political satire, or a good old guitar workout, but it always has a certain feel. It's complex, but it's got a warmth to it, it wants to bring you into the magical worlds it creates. Somehow, just way to much prog-related material lacks that warmth. Even cannonical prog does this from time to time- Gentle Giant is a major culprit. I think there's a fine line, but in general, if a peice of music has that feel then it's prog.