Guybrush

I know there are going to be many exceptions to this, but I feel that progressive rock is generally composed. Someone sat down and thought it should go like this and this and then there's a different theme here .. Think ELP's Tarkus, anything from Gentle Giant, Yes, National Health and so on. When there is improvisation, it's often because room for improvisation was written into the song.

Jamming is a different approach to music, although of course it is an approach that prog bands as well as all other bands might use to come up with interesting stuff to put into their compositions.

edit :

Ehf, most music is composed. I mean more elaborately composed than the average tune you might hear on the radio, like a Frank Zappa song might be (ex. "Montana"). I believe Dave Stewart from National Health would require his band mates to play his (ambitious) compositions exactly as he wrote them down to the smallest detail.

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