What are the conventions that make up the sub music genre of progressive rock? Try and come up with a list of conventions. Here are my ideas.

1. Longer songs (average of 5 to 12mins long).

2. Instrumental solo's and instrumental pieces in songs.

3. Use of other instruments from other genres (classical music and jazz).

4. Sophisticated Lyrics, considering socialist topics

5. Standard Rock Instruments- (Guitar, Drums, Keyboards)- always used.

6. Album based rock, (generally not chart music).

Experimental

Exciting (For us, but excrutiatingly boring and pretentious for many..But they dont understand)

Good musicianship (with the exception of Hawkwind) but I still like them..

Mysterious moods and atmospheres

Key changes and time signature changes in, yes you said it, long songs.

Enigmatic songtitles/Album titles/covers etc

Eccentric band members/Posh public school educated band members

The best music there is, quite simply.

All of the above plus

Not radio friendly.

lots of obscure bands

Ugly musicians

Concerts for 100 to 500 people.

timeless classic albums

often technically skilled musicians

 a number of concept albums

Cover art in a certain style

Focussed wrote: The best music there is, quite simply.

I'm not sure... but it IS sure that it's the best music I've heard yet....

I will limit myself to musical aspects (i.e., not addressing art, album covers, etc.).  Here are a dozen.  I'm sure that I will come up with more:

1.  Non-reliance on standard verse-chorus-verse form of most popular music.

2.  Less "linear," more "classical" orientation: i.e., more like a "score" - with a greater sense of counterpoint and "independent" lines - than a simple "vertical" building of guitar, bass, drums, keyboard.

3.  More extended, often "thematic" writing, leading to lengthier compositions to make room for "theme" statement, exposition (and, in some cases, "variation") and restatement.  This "thematic" writing (mostly in conjunction with lyrics (see below)) often leads to the creation of an album-wide "concept."

4.  Greater use of keyboards both for melodic, rhythmic and other structural purposes, as well as for "texture" and "atmopshere."

5.  Use of non-standard instrumentation, particularly including non-standard percussives, strings, and woodwinds.

6.  (Generally) higher-level musicianship, required in order to execute the more complex form.

7.  Lyrics tending to be more esoteric, and often based on fantasy, sci-fi, or literary references.  Greater use of lyrics in creating album-wide "concept."

8.  Greater use of non-standard time signatures and time shifting, as well as internal polyrhythms.

9.  Greater, freer use of dynamics to separate "sections" in longer compositions.

10.  Use of the studio as a conscious element in the creation of the music, especially vis-a-vis sounds effects, textures, atmospheres.

11.  Use of "external" sound effects, spoken word, etc. as elements of composition.

12.  Generally greater sense of experimentation and "free-form" composition, sometimes including elements of classical, jazz, celtic and other "world music" forms.

1- long -not boring- songs in general  (not essentially)

2- music that is listened with mind as much as heart, always makes me thinking about many stuff

3- very symbolic lyrics with very deep meanings changing everytime you listen to the songs

4- music that is good enough to survive from 40 years till now and never be boring

5- "speaking solos" many solos just gives you many meanings without anyone saying a word, and instrumentals that is better speaking than million words

6- musicians that are respectable, talented and highly creative

7- lots of keyboards

8- many changing rythms throughout one song, not just one rythm as in other kinds of music

9- changing key signatures a lot even in one solo, and very very dificult timing.

10- music that wants to deliver meaning and wants to say something not just "love, sex, drugs, death" as other many many many kinds of music

11- very very very melodic even while using strange instruments - i must say that there are many bands that are not that melodic most of the time as KC but i still love them, my favorites though are melodic (camel - ELP - VDGG - pink floyd - opeth)

12- even if i listen to slow, rock and roll, jazz, new age, blues, some old country, death - doom - neoclassical and all kinds of good metal. Prog is my favorite music that i think is the best

12- if i kept writing about prog i will need 20 pages

Prog has something that only Fusion has... musicianship

also...

a great way to get involved with history, emotions, feelings, colors and textures, that's why most of the songs are to long , a legend waiting to be told, the extreme use of ALL the instruments, even, incorporating other kind of instruments, and weird instruments (as the KOTO, CLAVICORD, FLUTES, HARPS etc) the use of rational and magnificent vocals and the perfect balance in between rock, jazz, classical and pop.

peace

We progsters tend to take our music (and sometimes ourselves) very seriously, and I'll be the first to admit I do too. But I couldn't help laughing when I saw the site below. Not exactly a definition of prog rock but sure worth a chuckle or two... 

http://www.btinternet.com/~archimedes/progrock.html - http://www.btinternet.com/~archimedes/progrock.html  

Could give 100 characteristics or conventions but I only need to use two words:

TRASCENDENCE VOCATION

Classic and Prog' music are composed to last for ever if posible, other genres only search for instant success even if the song or album is forgoten after 6 months.

Iván