I've been kicking this thought around for years.
I grew up listening to lots of stuff.--Mostly YES, GENESIS, MOODY BLUES, RUSH, PETER GABRIEL, ELP, PINK FLOYD, JETHRO TULL, KANSAS, etc.
Still do!!---Still growing up I guess.-lol

When I listen to this stuff with other people, I'm always asked "What kind of music is that?"
I tell them it's Prog and try to explain "Progressive Music".
Always turns into a snowball rolling towards hell!!--I can't say cuz I really don't the answer.
I've never heard any of the above mentioned bands refer to themselves as a Prog band.

I've heard many of one's thoughts on this matter.
Always sensible but exactly different opinions.
I consider that as a good thing as it never turns into arguement!!--BUT, it still doesn't explain what "PROG" is.

"PROG" isn't pop, soul, rap, jazz, classical, opera, blues, country, rock, and all of the others which I can't name!!-lol.

My opinion is that PROG is one of any or many combinations of the above mentioned musical forms.
It can all be great by design based on being able to get 3 or more musicians willing to mingle their thoughts and talents with disagreements, arguements, and egos set aside.
You can come up with some pretty good shtuff with so many options sitting out there.
Why is there not more of this?

I didn't realise how much good stuff that I've been missing until I crossed paths with S.A.!

My definition of "PROG" is: "It's what we uffing like!!"

What might your thoughts be on this?--I'd like to hear your opinions!!

This is an interesting question (see Requests thread).  It varies so much, doesn't it?

Take Genesis, for example:

Genesis to "Lamb": prog, without a doubt.
Genesis post-Lamb...hmm.  Could be at times, still did ling songs well into career with themes, sections, etc.

Gabriel, on first album - yes v prog.
Gabriel on "So"...not convinced. 
When did he change??

Phil Collins solo - no way, never was remotely prog!

Hmm, the more I think about this the harder it gets...

bogl

Hi there Nenes and welcome to the Forum !!

Excellent selection of bands you have listed ...

D.C.

Glad you appreciate the 'Radiohead' Silver !!

Damn fine band who I hope to be playing more of very soon.

I myself think of progressive as a genre
created by the music industry
as a place to put bands that have a sound
that is so original that it defies categorization.

Many different people seem to have many different ideas
about what belongs in the progressive slot or not.
I have seen some crazy stuff categorized as progressive.
And the other way around.
Whatever...

To me personally there are five genres of music;
PRACTICALLY PERFECT, GOOD, OK, BAD and ABSOLUTELY TERRIBLE!

agree GG (hello everyone)!

so...progressive the noun vs. progressive
the verb.

at the time, we didn't think of  led zep or the who
as being different from yes, pink floyd, mahavishnu
or even... deep purple for that matter.

college radio programmed music like gil-scott heron,
the chambers bros., vangelis, tomita between the
"classic art rock".

my philosophy has always been "genres are for
record stores".

p e a c e
kirk

I also forgot symphonic prog rock