Music Theory and Jamming

There is a very good reason to learn at least the basics in Music Theory, and that's for being able to have a successful jam session. Sure, if you have some songs planned out, it can work fine, but there's not much creativity going on in that.

Guitar players need to know the name of the chord they're playing. There are several sites on the web that can help you out with that.

Bass players need to be able to hear the name of that chord and know exactly what notes to make a successful bass line. Check out the Bass Player Magazine's website for some tips.

Drummers need to at least understand the basics of time signatures, time changes, and what that means for their beats. Google it.

Going a step farther, they need to be able to know what "I IV V" or "II V I" means. Here's something a lot easier to explain in text, so I'll give you some help on that. My explanation will assume you've taken some theory.

I is the "root" chord. Let's stick with a C Major. All of your chords will usually stick with the same notes, so you won't find anything outside of C Major in your other chords. The rest go as follows -

II - Dorian (Written as D-7 when using C as the root)
III - Phrygian
IV - Lydian (Written has FMaj7 when using C as the root)
V - Myxolydian (Written as G7 when using C as the root)
VI - Aeolian (Written as A- when using C as the root)
VII - Lochrian

So a I IV V in C would be C Fmaj7 G7

Or a II V I would be D-7 G7 C

Hopefully that makes sense. If you have any questions on this, I'll be glad to answer them.