I want to pick out songs, but I don't know which chords to use. How many times have you said this? There are so many answers to this, but let's start with a little "schooling" theory. It can be said that the major scale is the source of all composition for songs and their creation.
Every song is in a certain Key. The major scale of the key can be used for determining the notes in the major chord for that key, as well as other things. Some methods say that it can also be used for determining the chords to be used in the key. In the key of C, for example, the major scale notes are C, D, E, F, G, A, B, and C again. It has been said that to determine the chords for that key, you should build a triad on each note and you will have the chords for that key. That is somewhat true. Let's look at the results and then we can examine them.
Here's what you will get by building the triads. The chord names have been given above the triads so that you don't have to be able to read notes to understand this.
First of all, you can see that the C major chord is repeated at the end, so you really only have seven possibilities from this method. Now, if you are an advanced player, you have seen and used a diminished chord, such as the B diminished triad shown. But if you are not, you only have six choices from this method (and how many times have you seen a diminished chord in the sheet music for contemporary songs?). Are all songs in each key created from just six possible chords? That's just nonsense.
Let's take a look at the chords for a couple of contemporary songs. The rock song "Back in the U.S.S.R.", by the Beatles, would use C, Eb (E Flat), F, and G if it were in the key of C. You won't see an Eb in the chords shown above. The Bo Diddly classic "Who Do You Love" would use the chords C, Bb, and Eb. Again you won't see the Eb listed or the Bb. So what chords can you use? Is there a rule or something to guide you?
The first rule for Chords in Songs is that every key has THREE PRIMARY CHORDS. That's a true fact. There are three main chords for every key. Click the button below to learn how to figure out these three main chords for any key.