Probably the most influential band from the Progressive era of Rock Music would no doubt be King Crimson. I can't think of a single Progressive group during the entire period of the 1970's that didn't point to them as a guiding light and inspiration. Probably the most logical progression and evolution from the Psych period of the mid-late 60's, mixing the technical proficiency of Jazz with thematic elements of Classical, Progressive or Prog-Rock as it became known was the music you listened to and didn't dance by and it certainly didn't adhere to the edicts of Pop music which said everything had to be done and said in three minutes or less.
And clocking in at just over 9 minutes, tonight's track The Court Of The Crimson King exemplifies what the form was all about.
Needless to say, when it was first released in 1969, In The Court Of The Crimson King was a staple in the diet of most FM underground playlists and it has gone on to achieve the reputation as being one of the milestone albums of the genre and the start for what has been a long-lasting legacy of a band which is still together (although the only original founding member Robert Fripp is still there and the band claims to be on hiatus) and still regarded as one of the great innovators in Progressive and Alternative music.
And for the next 9 minutes you'll get to hear why.