If I am playing on the scale of G major which have the keys G A B C D E F#, the chords of the major scale are G major, A minor, B minor, C major, D major, E minor, and F# diminished.

I am curious if there is a fast way to determine the notes in these chords. I know major scale chords have the pattern as Major Minor Minor Major Major Minor Diminished, but like for example:

For the second note in the G scale (A): I have to map out the A minor scale, then locate the (1,3,5) fingers in that scale, and then finally I have the major chord in that scale but that takes time. Or is this something you just have to memorize?

3 Answers 3


Diatonic Chords

First, as Tim also mentioned, stick to the key of G. You shouldn't be considering "an A minor" scale at any point.

  1. Write out (or think) the notes in G
  2. Start from the note you want to make a chord from
  3. Take every other note (intervals of a third)

That's how you do it at first. But the more familiar the (G) scale is to you, and the more you work with these notes as both chords and arpeggios, you just start to memorize them naturally.

Chord Formulas

Also, just as you should consider G as your frame of reference when harmonizing the diatonic chords of the entire scale, I'd also learn to use the chord root as a frame of reference when thinking about individual chords. Because remember that an Am is a chord in other keys as well. And it's helpful to be able to build the chord by itself without first placing it in a key.

So you already know the qualities of the diatonic chords (Maj7, min7, min7, etc). Now learn the formulas for each of those chords. For example a minor 7th is: 1, b3, 5, b7.

  1. You know you want an A minor chord
  2. Use the parallel major scale as reference (A major): A, B, C#, D, E, F#, G#
  3. So you take the 1, b3, 5, and b7 of that A major scale to get A, C, E, G
  • Thank you. Yes I know the formula for the chords like minor7th, major7th, Dominant seventh, major, minor, etc. I just have to practice more I guess and know the scales really well. One question when you say "Take every other note (intervals of a third)", does intervals of thirds mean 3 semitones? I am always confused do I calculate in semitones or whole notes? Since G to A is 2 semitones and that is not a interval of third correct? Oct 13, 2017 at 17:53
  • By "thirds" I'm not not talking about half-steps or whole steps because an a third could be a different amount of those steps depending on context. For example a major 3rd is 2 whole steps where a minor 3rd is 3 half steps. I mean it generally as in it could be either minor or major.
    – user37496
    Oct 13, 2017 at 18:23
  • 1
    A G major chord has a major 3rd interval (G to B) and a minor 3rd (B to D) contained within it. But if you start from a G scale and just take every other note (GMaj = G, B, D; Amin = A, C, E, etc), you'll get the same result. Each of those intervals could be called a diatonic third because they are thirds but change major/minor quality to stay in the key of G.
    – user37496
    Oct 13, 2017 at 18:25
  • So I noticed that when playing the first chord G Major (has a major 3rd interval (G to B) and a minor 3rd (B to D)). Then when playing A minor (has a minor 3rd interval (A to C) and a major 3rd (C to E)). Is that a pattern? For major triad it's major third interval then minor third interval and for minor triad it is minor third interval and major third interval? Oct 13, 2017 at 18:44
  • 1
    That's correct. The 3rd degree of the scale/chord is what makes it minor or major. As for the upper interval from the 3rd to 5th that obviously changes as well when you lower the third. The interval in either a major or minor chord from the 1st to 5th is a perfect 5th (G to D, A to E). That part stays the same. So in say G major B to D is a minor third, but when you lower that B to Bb to make a G minor chord, that distance to D increases by a half step which then makes the upper interval a major 3rd. But, yes, that pattern sticks.
    – user37496
    Oct 13, 2017 at 19:19

You could do it that way, as you say, take the second note A, then count up the A minor scale, 1,3,5 - A,C,E, then the B - 1,3,5 - B,D,F#. It works. The other way would be to stick firmly in G, so chord I is 1,3,5, chord ii is 2,4,6, chord iii is 3,5,7 (B,D,F# =Bm), except that takes you over the 8, as in chord vi is 6,8,10 (E,G,B =Em) but maybe that's not too bad.

Otherwise, as you guess - just learn them. There are many songs that use six out of the seven chords - play them in many different keys. I guess your instrument is piano. On guitar, it's probably easier to think in terms of relative fret positions for certain chord shapes - which isn't really an option on piano.


Just know your scales. I mean KNOW them. What notes are in them, how they're laid out on the keyboard/fretboard. You can't even BEGIN to think about composing or improvising until you know the map.

  • 2
    "You can't even BEGIN to think about composing or improvising until you know the map". Of course you can. I fully agree that you should aim to know scales well. The more you learn your instrument the better you'll get. But let's not reinforce the myth that you need to master everything before you even begin making real music.
    – user37496
    Oct 13, 2017 at 17:26
  • Not everything. But if you don't know the language, it's hard to read a story, let alone write one. And we've seen the sort of conceptual messes people can get into here often enough!
    – Laurence
    Oct 13, 2017 at 22:43
  • Knowing scale notes on a fretboard won't necessarily help in finding chord shapes. It always will on keyboard.
    – Tim
    Oct 14, 2017 at 7:54
  • Indeed. Guitarists who are interested in harmony and 'theory' would be well advised to find their way around a keyboard too.
    – Laurence
    Oct 14, 2017 at 17:50

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