Is it acceptable to use a Maj7♯5sus4 chord? Avoid note/interval clarification

Question

I have been looking through possible triads over bass notes and found an odd one.. F minor triad over B bass note. I rearranged the notes to give me a particular 7th chord 1 4 ♯5 7. Basically a Maj7♯5sus4 chord.. it seems to come from the 3rd mode of harmonic minor, Major♯5. It sounds really weird.. probably due to the tritone built inside this 4 note chord but yet it has a major 7th. Rearranging it more I got this chord 1 ♯5 7 11. Here are the questions:

1) Is the 11th in this chord 1 ♯5 7 11 an avoid note? There is no 3rd in this chord but it seems heavily implied anyways since it mostly came from the Major♯5 scale. It doesn't seem to help that it also forms a tritone with the major 7th...

2) When it comes to avoid intervals (in context of chord voicings) is the b9 interval the only interval I should watch out for? For example B E G C for C Maj 7. Or is there more avoid intervals (perhaps ♯11?)?

PS: A probable use for this chord for a progression may be D min - C Maj7♯5sus4 - C maj for those who want an example.

Answer 1

Two things to start off:

1) If you have something over F minor, you've got a polychord. B over F minor is B-D♯-F♯ over F-A♭-C. From your question I'm guessing you meant "F minor over B", which says it's an F minor triad over a B bass note.

2) If the bass note isn't a tone of the chord it's being played under, it's a "non-harmonic tone". It's not considered part of the chord, because chord symbols are a shorthand for musicians to realize the harmony. Fm/B says a B is being played, but it must be in the bass - and it can ONLY be in the bass. It can't appear anywhere else. If you had Fm/A♭, you can have more than one A♭ in the voicing.

That said, you've got a chord symbol of F minor. Chord roots aren't randomly chosen from a set of pitches - they indicate the root progression. When you have chords that can be interpreted in more than one way, it's the root (and not the bass) that dictates what the chord name should be. Since your chord is Fm, you should have an F root.

Moving forward from there, you might decide that the bass note could be doubled somewhere else in a voicing, and should therefore be part of the chord name. Having identified the root as F, you've got F-A♭-B-C. You might call that Fm(add♯11).

When you say it's "basically a Maj7♯5sus4 chord", I'm at a loss for how you get there. The major 7th of F is E (not in the chord), the major 7th of A♭ is G (not in the chord), and the major 7th of B is A♯ (not in the chord). The only way it's a major 7th of any kind is if you're now considering C as the root.

Since there's no context for how this set of pitches fits into a progression, I'm not sure there can be a clear answer as to what the avoid tones should be.

Answer 2

First of all you can play anything, it does not have to follow a set of rules. Music harmony theory expresses a set of guide lines for western multi-voice music. When it comes to a single chord there are no "avoid" notes (I realize I may be contradicting some advanced jazz chord textbook but I stand by the statement as it relates to artistic choices as opposed to classic harmony theory). In my opinion the Maj7 (♭9) sounds great and I often use the ♭9 when soloing over Maj7. Although the 4th is deemed an "avoid note" even in classical music (going way back) I would not necessarily AVOID it.

In the context of vamping over one chord if it sounds cool use it. For example min7 (sus), which is just baring all the strings of a guitar in standard tuning, sounds very cool.

What you really need to watch out for is the movement from one chord to another. This is where choices matter. You cannot haphazardly meander about from chord to chord and expect it to make musical sense. As for avoiding the 4th, if you are resolving from V7 to I it would not be advisable to use the 4th on the I. However a suspended resolution V7 --> I-sus --> I sounds great! That is where the term sus comes from. The 4th of the I is the ♭7 of the V and holding it over the I chord "suspends" the resolution. So you see the context matters. The real question you need to ask yourself is "what function do these notes serve in the context of the whole song".

As for b9 and other notes that are "out" relative to a chord or key, these can also serve as "leading tones" to create more tension and resolution. Over a dom-7 chord I often like to use every note that is missing to create extra leading tones (w/o being overtly chromatic). For example, the ♭9, ♭5, maj 7, ♭3. On the guitar in standard tuning this amounts to playing off the fret in between the two frets used to play the dom-7 chord in A-form.

Music is more about the movement from one chord to another (i.e. derivatives) as it is about the current chord.

Answer 3

The chord is an (incomplete) diminished seventh chord over a pedal point: B°7/C. It comes up on occasion in the classics; most notably, it is the first chord (following the opening unaccompanied melody) in Bach's Toccata in D minor (https://en.m.wikipedia.org/wiki/Toccata_and_Fugue_in_D_minor,_BWV_565). Per classical rules, it resolves to a triad on the same bass.

Pedal points are rare in jazz, but they occur (e.g. Gershwin's A Foggy Day). Try using your chord as a passing diminished seventh over a pedal point:

G7 | F/C B°7/C | Gm7(/C?) C7♭9 | F6.

You can solo over B°7/C just as you would over B°7, except that C♯ is clearly not such a great note to lean on. (Neither is C, in my opinion.)

(Note that B°7/C and C7♭9 are exact inversions of each other: a specimen of "negative harmony," of which I'm not really a fan, but it helps give consistency of harmonic color to a progression.)

Answer 4

A probable use for this chord for a progression may be D min - C Maj7♯5sus4 - C maj for those who want an example.

Just to confirm: C Maj7♯5sus4 would be C F G# B

A P4 above the root would normally be an avoid tone, but in a sus4 chord isn't the point to play it? Effectively the P4 becomes a sort of chord tone. I have to say 'sort of' because of the classical versus jazz confusion about the term suspension.

Given that the F is supposed to be a suspension E would seem to be the tone to 'avoid' and with a raised fifth G# then the unaltered G natural would be the other 'avoid' otherwise how will those tones be heard as the chord alterations?