Why does the IV - V♯ - I chord progression work so well?

Question

The song Long Away by Queen does this, but it's a pattern you'll probably find in many songs.

Basically, I've noticed that when moving from IV to I, a V♯ or V♯maj7 chord is sometimes used as a transition. To my ears, it sounds amazing. I've started to use this progression in my own songwriting, but I still have no idea why it works.

My initial guess would be that this chord creates tension that is resolved by the root chord, but I don't really see that when looking at the notes.

Is there any particular reason why this chord works this well in these situations, or is it just an "if it sounds good, it is good" thing?

Answer 1

First let's not look at it as a ♯V chord, but a ♭VI chord. This chord naturally occurs in the parallel minor and can easily be borrowed.

Let's look at how the notes move with a sample progression in the key of C:

IV      F  -  A  - C
♭VI(7)  A♭ -  C  - E♭ - (G)
I       C  -  E  - G

If you look at this progression without the 7th, you'll notice a few different different features it has. First and most noticeable C (the tonic) is a common tone in each chord. You can think of this as linking all the chords in the progression. Next the progression descends chromatically from A (the submediant) to G (the dominant). In general chromatic movement across multiple chords is typically extremely effective especially when dealing with chords outside the key. Last the 3rd of the tonic is approached in a circular fashion going from F to E♭ to E. It's not quite a resolution, but in the context of the progression it can be viewed as a a resolution similar to the Neapolitan chord to dominant to tonic functions.

With the seventh included in the progression all that really changes is there is another common tone between the ♭VI and the I as G is common in both.

One of my favorite progressions is I - ♭VI - IV - V which is follows similar logic as mentioned above just with the added V chord to round it back to I. I personally really like using the ♭VI chord because in my opinion it sounds slightly darker in nature, maybe because it uses the ♭3 of the key or because it is from a minor key, and in my option gives the progression a slightly darker sound.

Answer 2

There are lots of theory and technological reasons why this works, but I think the question is about its effect on the listener. The #V (or #V7,rather than #Vmaj7)) can be thought of as the dominant of #I - as in heralding a key change rather than a modulation.Most listeners would expect the song to go up in pitch. What a surprise when it doesn't. The change from IV - #V, a minor third up,(or aug 2 here) is also diatonic, and listeners are hauled to a blend of notes that 'don't belong here'. So, there's one shove sideways, followed by a trick. It's a mini roller-coaster.

As stated earlier, there's all the stuff about parallel keys, relatives, etc.,hopefully someone else will provide those details. And I'm not sure if it's a #V or bVI!

Answer 3

Chords that contain the #5 of the key have a dominant function in that key. For example, in the key of C, the #5 = Ab and chords that are often used to resolve to C major include: Fmin, AbMaj, G7b9, and Dm7b5, all of which contain the Ab note.