Hey all,

I've been having an interesting discussion with Tom Colohue about a seemingly simple, but actually very confusing little chord progression... basically, we seem simply unable to grasp how it works. Here it is:

Am - Em - Bm - F#
Tonal centre: A

Keep in mind that the piece in which this progression is used is based on A as a tonal centre. Because of this, the progression doesn't seem to make sense tonally nor modally... at least, the sense behind it seems to stretch beyond our combined knowledge of theory!

So, MT, show your overwhelming theory knowledge and help us understand this progression!

If you were in Am, that would be I - V - iim - VI.

That's like a backwards VI - ii - V - I. The full cycle being IV - vii - iii - vi - ii - V - I.
actually it would be i-v-ii-VI (iirc) the VI-i starting over is a real strong resolution back to the root.

Am - i
Em - v
Bm - ii
F# - VI
Last edited by z4twenny at Oct 24, 2009,
I always start by taking my focus away from key initially and look at relationships. Here there is an obivious a chain of fourths Root Movement = A - E - B - F# (down a P4, down a P4, down a P4).

Depending on rhythm, dynamics, and various other elements in context you could use any one of those chords as the tonal centre.

You say you've establishing A as the tonal centre.

The minor chords provide an interesting aspect to the changes.

The minor third in the Am is C. This moves down a semitone to become the fifth in the Em (B). This B then remains as a common tone between the Em and Bm chords.

The minor third in the Em (G) then moves down a half step to become the fifth of the Bm chord (F♯ which then remains as a common tone between the Bm and the F♯ specifically, the root of the F♯ Major.

The F♯Major is the VI chord in the key of Am (as opposed to the naturally occurring ♭VI normally found in Am). It isn't "in key" because it's arrived at through following a chord sequence that hasn't been derived from a diatonic starting point but through a pattern of root movements (Chain of Fourths).

The F♯ Major works well though as it leads us back nicely to the Am by continuing that same "third-of-the-chord-moves-a-half-step-down" idea that got us to the F♯ in the first place. This time though instead of moving down to the fifth of the new chord it moves down to the ROOT of the Am - (The third in F♯ being A♯.

you follow?

EDIT: you could even go to D - Dm - Am after that F♯ for a fairly common Plagal cadence.

EDIT II: Blue Strat hit on the same idea i was going for - just explained in a different way and a bit quicker than I did..
Last edited by 20Tigers at Oct 24, 2009,
♪♬"I love to tu-u-u-u-rn yo-o-o-u-u-u o-o-o-on."♬♫♩

- It's a nice progression.
Quote by 20Tigers
*Chain of Fourths, thirds descending in half steps*

Sexy. Never seen or heard stuff like this. Theory really is endless.

Thanks, mate!