After almost a year of teaching myself music theory, I understand most of the process of making music (that doesn't necessarily mean I have every scale, chord, etc memorized... that's a different story). However, there are 2 things I still need clarification on.

1) This is a 2 part question: chord progressions aren't difficult to understand... but is every single chord in a song considered part of a progression? This pertains more toward bands with one guitarist, like Dream Theater for instance, when a riff contains all single notes with one power chord thrown in every other measure (just an example). Also, in progressive music (which is what I'm mostly into), we all know that songs can get pretty long or have several different riffs. Would it be ok to have several different chord progressions in one song?

2) Time signatures... they took me forever to figure out. Now that I understand them, I'd like to include odd time signatures in my music to give it a prog feel. I'm not entirely sure how to incorporate them, though. Do you simply say to yourself, "I'm going to make this part of my riff in 7/4 time just for the hell of it", or is there something I'm overlooking?

Any help would be appreciated!
Quote by flapz
Would it be ok to have several different chord progressions in one song?

Absolutely, be creative.

As for odd time signatures, write a riff or strumming pattern than would fit in the odd time signature. Listen to the bassline on Money by Pink Floyd, it has a good 7/4 feel.
For the chord progressions question, well, your favorite music is called progressive. :P So I guess that answered your question.
i also have been taking theory lessons for about a year know and i think i can answer your questions

1)No and Yes. Basically over riffs there are usually no chord progression, for example, in the dance of eternity(another dream theater masterpeice) their are many riffs which are played by guitar,keyboard and bass and no instrument is really playing any chord or triad, and even though john throws in a couple power chords here or there is mainly to add effect. But riffs can have chord proggressions, for example in Liquid Tension Experiments's Paradigm Shift the main riff comes in later over the keyboard playing a very obvious ascending chord proggresion. Also there are usually many chord proggresions in a song

2)Well yes, because once you have an inner sense of odd time signatures like 7/4 or 5/8 and so on, you will find yourself deciding to make riffs in those time signatures. And like pwrmax said, be creative, add a couple notes, put in a couple power chords.

Well hope that helped