intervals

It's a way to speak more generically about chords. It's vital for understanding chord construction. It's what allows you to learn an E chord, and then without learning an entirely new shape, to easily know an F chord.

Ultimately, once you're intimately familiar with the basic chord shapes and have the fretboard memorized, it will help you understand how you can play any chord in any position, which I think is one of those big steps in intermediate guitar progress.

It makes all the difference in the world.

If you're solo'ing over a particular chord, and you're playing the wrong intervals, it won't sound right.

The intervals combine to give chords their sound qualities. Intervals are what make some notes sound like they belong with other notes.

Understanding western music pretty much starts with understanding the intervalic relationship of major scales.

Major Scale: 1 2 3 4 5 6 7
Pentatonic: 1 b3 4 5 b7
Minor: 1 2 b3 4 5 6 b7

I think. Oh, seriously. check out Speed Mechanics for Lead Guitar by Troy Stetina. It has lessons on intervals and a ton of other stuff. It's freaking awesome.

I get that part of it.. but how does a 'perfect 5th' help out in that situation? He wasn't even teaching them in relation to notes, but as shapes.

Perect 5th means there are seven(thanks noteboat) semitones between the two notes. But if you are talking about harmonized stuff. it's different. A perfect third, for example, would mean that you would play say, an A. Say this is the major scale. You would next play the note that is the 3 notes away from the A, that is in the scale. which would be an A.
------------------------------------------------
------------------------------------------------
------------------------------------------------
------------------------------------------------
5-----7--------9-------------------------------
5-----7--------9-------------------------------
^ Harmonized thirds.

Actually, a perfect fifth is SEVEN semitones. The inversion, a perfect fourth, is five semitones.

Doh. I just remembered that. Power Chord=Perfect fifth. Thanks Noteboat.

This goes back to the second thread of this topic, scales, I read in a thread a couple months ago that said to get a major pentatonic scale you leave out the 4th and 7th tone of the major scale, and to get the minor pentatonic leave out the 2nd and 6th tone of the major scale, and to get the minor scale lower the 3rd 6th and 7th a half step. Is this correct?

Correction , it was the 4th thread.

I must admit, I've not heard of a perfect 3rd. A perfect interval is so-called because the inversion is also a perfect interval. If you take a major interval and invert it you get a minor interval and vice versa.

Greybeard's right.

Only unison, fourth, fifth, and octave intervals can be perfect.

If the others are in key, they're major.

So what makes an interval perfect? I think I understand the difference between major and minor (ie major 3rd is root to 2nd of 2 semitones and another 2 semitones to major third, a single semitone from 2nd to 3rd for a minor 3rd ) but fuzzy on the perfect aspect.

Also, I've learned the fretboard as to the notes. Now I'm trying to learn it as to intervals (I pick a note and can find all the intervals above and below it in that area of the fretboard). Is the formula for major pentatonic, minor pentatonic etc mentioned by painthorses solid?

Although, I'm learning the fretboard logic forms, which is very handy, I'm trying to learn them with the intervals in mind so I can purposely get sounds and harmonies going rather than just experimenting as to what sounds right.

Thanks

Let's take the interval C-G. That's a fifth interval... starting from C:

C-D-E-F-G-A-B-C

Now let's invert it, going from G-C. That's a fourth... starting from G:

G-A-B-C-D-E-F#-G

Now let's try doing that with a major interval, like C-E... starting from C:

C-D-E-F-G-A-B-C

and again, inverting it E-C:

E-F#-G#-A-B-C#... whoops! C isn't in the key of E. So a major interval, when inverted, gives you an 'out of key' note. A perfect interval doesn't - that's why they're perfect.

The only perfect intervals are unisons, fourths, fifths, and octaves. Build chords on those and you get I-IV-V, the major chords in any major key... and the reason we get 'three chord rock & roll' - every major chord is in the home key, and the home key chord (the tonic) will appear in the key of the other two major chords - the chords in C are C-F-G, the chords in F are F-Bb-C and the chords in G are G-C-D.

Kinda neat how it all folds back in on itself, huh?

Somebody buy this man a beer!

Great explanation Tom.