1. Experiment. Create short chord progressions (2, 4, or 8 measures
long, 1 or 2 chords per measure) from these diatonic chords. Do this in
different keys. Try different combinations of the diatonic chords. Keep the
ones you like in an "idea notebook".
If you don't play a chord instrument or you don't have one handy, here's a
web-page tool you can use to play these chords. Just choose a key and play
the chord buttons:
Choose a key:
2. Play the sequence. Practice playing the sequence of diatonic triads
(I - IIm - IIIm - IV - V - VIm) in
several different keys. Eventually, you should learn to play this sequence of
chords in all the major keys.
3. Analyze songs.
Look at a chord progression from a song you like.
Figure out what key the song is in (which pitch sounds like the
Examine each chord and see if it's a diatonic triad in that key.
Depending on the song, all, most, or very few of the chords might be
major-key diatonic triads.
For the chords which are diatonic triads, label them with
their Roman-numeral symbol. For example, here's a (simplified) short chord
sequence from Bob Dylan's "Like A Rolling Stone", in the key of C:
You would add Roman-numeral symbols like this:
Important note: Make sure you label only the diatonic
chords. For example: Say you're analyzing a song that's in the key of
C, and you see a D (D major) chord. Well, you could
go ahead and label this chord "II" ("two major"). But, "II" is actually
not a major-key diatonic triad; IIm ("two minor") is.
So, you should not label that D chord. Remember, the purpose
of this activity is to recognize the diatonic chords, not to just
slap a label on every chord.
When you've labeled the diatonic chords in some songs, look for
patterns. For each Roman symbol (I, IIm, IIIm, etc.), how often is that
chord used in popular songs? Are there patterns where certain Roman symbols
often follow certain others? For each Roman symbol, do you notice certain
"emotional effects" for that chord?
4. Learning by ear. When you're figuring out a song's chords by
listening to the song—trying different chords, looking for the chords
which "sound right"—it's a good bet to try diatonic chords in the
song's key, because the diatonic chords are used so often in songs. With
practice, you may get a feel for when a chord in a song "sounds diatonic" or
not, even before you try to find which specific chord it is.