# The transition from G to C in guitar chord progressions

I'm now learning chord progressions and melodic intervals. The way in which I learn chord progressions is by identifying the intervals between the bass notes, so when I play the chord C and then G , according to the bass note there is a perfect fifth interval that allows me to identify that sequence as C-G ascending.
As far as I noticed, when playing the key C in the piano and then the G in the octave below I get a perfect fourth descending interval.

And here comes my question: when playing the chord C in the guitar and then chord G, the bass note actually goes from the note C to the note G in the lower octave. So this sequence of notes is heard as if it's actually a perfect fourth descending interval (like F->C).

How can I prevent myself from such an error of ascribing this chord sequence to ascending fourth rather than a perfect fifth ascending?

• "How can I prevent myself from such an error of ascribing this chord sequence to ascending fourth rather than a perfect fifth ascending?" By not thinking of progressions this way. If we name chords by letter and don't specify the octave, then there's nothing to say which octave each is in. C to G may ascend a 5th or descend a 4th, so memorizing only one of those facts isn't useful. It seems to me a better approach would be to learn about tonal function (e.g. "G is the V chord, or dominant, in the key of C"). Commented May 13 at 19:51
• It might yield more useful answers if you edit to talk about where you got the idea to memorize chord pairs as one-way intervals. Commented May 13 at 19:53
• why not? if in the leadsheet it says : play C G it supposed to be C G and not C F? If I pay attention only to the bass, there is no difference!. what in the chord can help me understand that it's C-G? or should i relinquish this idea of chord intervals? in every place they say that for chord ear training you need to learn how to identify intervals...
– Ynk
Commented May 13 at 20:11
• Yes, you should relinquish the idea that "G is a fifth away from C," unless you also memorize "or a fourth away, if we're descending." Identifying intervals can certainly help. For one thing, it can help you identify the chord itself (inside the C chord, to hear the thirds); and it can be very useful to be able to recognize the bass line (as if it were a melody of its own). But beware! The bass note might not be the root. You might have a C followed by a G in the bass... but the chord is still C major, just in 2nd inversion! But we put all the clues together, and the more clues the better. Commented May 13 at 20:21
• Actually, I think I see an even more fundamental misunderstanding. "If I pay attention only to the bass, there is no difference [between G and F]! What in the chord can help me understand that it's C-G?" The misunderstanding here is, you can't identify chords by looking only at the bass notes (because they're not all root position). You could give someone a bass line and ask "what chords are these," and there could be no single right answer. There could be several different "good ideas," and maybe some bad ideas that don't work well, but it takes more than one note to make a chord. Commented May 13 at 20:30

## 4 Answers

How can I prevent myself from such an error of ascribing this chord sequence to ascending fourth rather than a perfect fifth ascending?

By not thinking of progressions this way. If we name chords by letter and don't specify the octave, then there's nothing to say which octave each is in. C to G may ascend a 5th or descend a 4th, so memorizing only one of those facts isn't useful. It seems to me a better approach would be to learn about tonal function (e.g. "G is the V chord, or dominant, in the key of C").

Identifying intervals can certainly help. For one thing, it can help you identify the chord itself (inside the C chord, to hear the thirds); and it can be very useful to be able to recognize the bass line (as if it were a melody of its own). But beware! The bass note might not be the root. You might have a C followed by a G in the bass... but the chord is still C major, just in 2nd inversion! But we put all the clues together, and the more clues the better.

How learning cadences and other chord progressions can help me without relying on the bass note? because I do learn cadences and other chord progressions.

Well, like I said, hearing the bass notes can be an important clue, just not the only one. For instance: I might hear some chords and say "I know there's a C, and then something that I'm not sure of, and then a G." The chord in between the C (tonic) and G (dominant) is probably a common "predominant," like ii or IV, that is Dm or F. So already I'm using my knowledge of typical harmonic motion to limit the expected options. Then it might help a lot to hear the bass line. If I can hear that the bass note is a D, then it's almost certainly the Dm, not the F chord. If I'm not sure what the bass note is, then hearing intervals might help. Perhaps the bass goes "C G D G." I realize, just from the sound of the chords on top, that the C and the G are the same chord, both using C chord. But then I hear a descending fourth and realize that the third note is a D, and that helps me identify the Dm chord. OR it could be that I can't recognize all that. Perhaps I can't make out the bass note at all. But then I could listen to the quality of the chord, and think "that sounds like minor," and figure out from that that it's probably the D. So all these tools: recognizing melodic intervals, recognizing intervals that are played simultaneously, and recognizing common harmonic patterns, can all work together; if I can make out one piece it can help me guess another.

• thanks. but this approach seem to take time for the analysis... how can I do it instantly by ear?
– Ynk
Commented May 14 at 16:33
• @Ynk Much like Divizna's comment, just repeated practice. To be able to recognize all harmonies instantly by ear is quite an accomplishment! Before you get to that level, you would pass through "being able to recognize some chords instantly, and puzzle others out with a bit of time and effort." And still maybe be stumped by some. Practicing harmonic dictation, with examples that start simple and gradually increase in complexity, will train this skill. Commented May 14 at 16:35
• @Ynk And honestly, even if our brain goes through some of the steps of logic I described, it can do so instantly and subconsciously. If you play "Twinkle Twinkle Little Star" and stop before the last note, your brain knows which melodic note and chord to expect, and it does that based on common harmonic patterns, whether we think about them or not. Commented May 14 at 16:55

C - G is a 5th up or a 4th down. C - D is a 2nd up or a 7th down. That's it really. Modify your assumptions accordingly.

Playing those particular shapes for C and G on guitar, the lowest notes(roots) actually do go a 4th down. From C on 5th string fret3 down to 6th string fret3. Nothing wrong at all - and it's reflected on the piano.

Bear in mind that the inverse of inversions (!) follows the 'rule of nine': P5 inverted makes P4. As in C>G = P5, G>C = P4.

Not at all sure that learning chords initially using intervals, particularly on guitar, is an excellent way. Most will simply learn the shapes concerned, often oblivious to the ramifications of any intervals at all. I know that's what I did. Only when I started teaching did that occur, for good or bad!

Another thing that crops up on guitar is that so many sites insist every chord must be in root position. On guitar, that's not only unnecessary, but frequently difficult to impossible. So, for my money, you're approaching chord learning on guitar in a non-intuitive (and not the best) way.

• so what is the best way for guitar chord ear training?
– Ynk
Commented May 14 at 16:34

Don't know about you, but when I play the G chord on the piano, the lowest note (bass, if you want, though I'd use that word for the whole left hand) is usually B.

The C chord doesn't consist of {c, e, g} in the small octave, or {c, e, g, c', e'} only. And the G chord doesn't consist of {g, b, d'}, or {G, B, d}, or {B, d, g}, or {G, B, d, g, b, g'} only.

They consist of the given tones in every octave, so for the chord of C, that's {,C, ,E, ,G, C, E, G, c, e, g, c', e', g', c'', e'', g'' etc.}. For the chord of G, it'll be {,,B, ,D, ,G, ,B, D, G, B, d, g, b, d', g', b', d'', g'' etc.}.

Behold, the C chord:

It's neither possible nor really desirable to play all of these at once, so that's where the voicing of the chord comes into it - a representative subset of the tones that belong in the chord. On the piano you'll probably choose three pitches to play, or four if you count the one from the melody too (unless you dedicate both hands to the harmony), on the guitar four to six.

The point is, the root of the G chord is not either the great G or the small g. It's G and g and also ,G and g' and g'' and the G from every octave at once.

Asking whether every G is a fifth above or a fourth below every C is not even the right question. It's both, because we're not talking one specific pitch, we're talking the whole class.