Why the chord on the third degree is major in this progression?

Question

I came across with this video

The chords are E - G♯ - C♯m - B

My question is: why is G♯ a major chord in this progression? I thought that since the root of the scale is E (major) the third chord (which is G♯) should be minor, unless the scale of this progression is not E major. Am I right?

Thank you! I would like you to explain me this. I'm just trying to understand how certain chords are used while playing a certain scale.

Answer 1

You are correct, the piece is in E major. If you use roman numerals to represent the chords, the progression can be written as: I - III - vi - V

The reason that the III chord is major, when it should normally be minor is that it is in fact acting as the "dominant" (V chord) of the following C♯m (vi). It's almost as if you were temporarily shifting into the key of C♯ minor. This is a common technique, known as a secondary dominant. It can be indicated in roman numerals as: I - V/vi - vi - V

See also:

• What is a secondary dominant chord? -- For more information about secondary dominants.
• https://music.stackexchange.com/questions/24171/trying-to-figure-a-chord-in-song/24183#24183 -- Mentions the same progression of G♯ - C♯m in E.
• Do all chords in a progression usually fit within a scale -- For a broader perspective of when chords can fall outside the scale.

Answer 2

While the G# could be considered V of vi, or C#min, the progression doesn't actually go to the vi, it actually goes to A, which is IV (ok, so the A is vi of the vi, whatever). So the progression is actually: I - III - IV - V. Or E - G# - A - B.

This is something we have all probably heard a million times, almost as common as I - IV - V. The III doesn't really function as V of vi, it is just a passing chord, much like a diminished chord in jazz.