“slash” chords, e.g. B/F♯ - are these only for inversions, or can any note be the bass note?

Question

I'm trying to work out whether it is technically correct to have a "slash" chord where the bass note is not one of the notes in the chord.

I thought the main reason for slash chords is to show which inversion of a chord to play.

However, someone has given me the chord progression B – B/A♯ - Gm7 – B/F♯ which shows a slash chord with an outside note in the base.

You will note that A♯ is not in B major.

But isn't it more correct to call that chord Bmaj7 rather than B/A♯ ?

Is there any valid case of having a "slash" chord where the slash note is not in the actual chord?

Answer 1

To answer your last question: Yes -- because it sounds cool.

A common gospel piano thing is a IV chord with dominant function because it's over the dominant in the bass, i.e. F/G (in the key of C).

Inversions were historically notated using a figured bass style. Slash chords are a relatively recent invention, and they can be used both for inversions and for other chords that don't fit "traditional" harmony.

In many cases it is not practical to extend your notation up through the chord members until you come to the "weird" note -- you'll end up with a weird 13th chord or something (which is just not accurate) and, in the case of the 13th being the bass note, inversion notation just doesn't go that high. It makes much more sense to just say C/G#.

Answer 2

The note behind the slash is often meant as the note played by the bass guitar, and if you are playing this in a band where you do have a bass guitar, it can even be ignored on the guitar.

In this particular example you see that the bass is actually a movement going down one note at a time (B A# G F#), where the movement itself is more important than if it fits perfectly within each chord. It is more like a simple bass melody than part of the chord. It is relative to the chords in much the same way the main melody relates to the chords.

The last note in the movement usually ends up on the ground note in the chord at the first beat in the following measure. Based on this, I would guess that the next chord in your example (which is the first in the following measure) would be an E.

Answer 3

I agree with the above, but sometimes the composer wants a basic chord eg. Cmaj, but with a bass note which is not contained in that chord ( C/G#) However this is a poor example as the G from the chord clashes with G#. In the example in the question, the bass line is moving down,so A# bass is good, and works against a Bmaj chord, which doesn't need to be played (or written) as Bmaj 7. Tim