Most two-chord songs feature a I chord (let's say C) and either a V or a IV (G and F, respectively). Why? Because the V-I and IV-I cadences are two of the most powerful cadences in music. You find these progressions everywhere in folk, rock, and reggae.
1. C - G - Am - F (I - V -vi - IV) This just might be the most popular chord progression in Western popular music. There is an actual mathematical explanation as to why it's such a pleasant progression.
The most important chord in the major key is the major chord, followed by the dominant chord, then the minor chord.
The I–V–vi–IV progression is a common chord progression popular across several genres of music. It involves the I, V, vi, and IV chords of any particular musical scale. For example, in the key of C major, this progression would be: C–G–Am–F. Rotations include: I–V–vi–IV : C–G–Am–F.
G, C and D are some of the most commonly used chords in popular music and are used in literally thousands of songs (we'll list some of the most well-known later). Also, they're not too difficult to learn and they sound really good together (hence their popularity).
But according to a study, major chords are not the happiest sounds in music. Although people do perceive major chords as more emotionally positive than minor chords, the happiest sounds of all are seventh chords – major or minor chords with a seventh added.
In Germany, Christian Schubart wrote many books on music. In his Ideen zu einer Aesthetik der Tonkunst of 1806, he shares his descriptions of each major and minor key. D minor, wrote Schubart, is a key of “melancholy womanliness, the spleen and humours brood.” He actually found D#minor to be sadder.
Pauer's key characteristics for D minor are that it: “expresses a subdued feeling of melancholy, grief, anxiety, and solemnity.”
The D major scale, harmonized in intervals of thirds, yields the diatonic triads in the key of D major. When we do this, we get seven chords: D major, E minor, F# minor, G major, A major, B minor, and C# diminished.
The two biggest problems beginners have with the D chord are getting the shape confidently under your three fingers and muting the bottom two strings. To help with the fingering, you can practice transitioning from a G major chord or A major chord to the D shape and back again.
The famous four chords used in many pop song progressions are the I, V, vi and IV chords of a major key. The roman numerals represent the numbers of the major scale we begin a chord from (1, 5, 6, 4) so in C major this would be C, G, Amin, F or in G major it would be G, D, Emin, C.
There are 7 notes in each key. Each note of the key can be a root for a chord. If we build chords on those roots with only notes from the scale (that is, staying diatonic), we get a set of 7 diatonic chords.
One thing to keep in mind is that the first chord of a song isn't always the key. It can be any of the chords in the song, and you'll want to be listening intently for that tonal center.