Confused as to why one scale fits four different chords

1. Do chords have to be in the same scale?
2. Are chords different in different scales?
3. How do chords relate to scales?
4. What are the 4 chords used in most pop songs?

Do chords have to be in the same scale?

In your average chord progression, most of the time all of the notes will stay in the scale that correlates with the key of your song. If the song is in G major, your chords will contain notes that are found in that scale- G major, C major, D major, E minor, A minor, B minor.

Are chords different in different scales?

The only thing that determines the name of the chord you are playing is the notes you play. Any time you play C Eb G you are playing a C minor chord no matter what scale is being used at the time. Any time you play C E G you are playing a C major chord no matter what scale is being used at the time.

How do chords relate to scales?

Scales and chords are interrelated. There are two sides of the same coin. A scale is a horizontal representation of a particular collection of notes and is built up in 2nds; A chord is a vertical representation of that same collection of notes and is built in 3rds.

What are the 4 chords used in most pop songs?

These four chords are the magic I, IV, V and vi.