Jazz Chords: How can a Bbmaj9 be explained in the key of A major?

Question

I'm looking at the sheet music for the song Sometimes in Winter:

https://www.noteflight.com/marketplace/4V9yWpCsl2ktvMaaOd0Tgh/sometimes-in-winter

It appears this tune is in A Major. In the 3rd bar, there is a BbMaj9. It sounds good, but I'm having difficulty explaining this chord. Is this a chord substitution? If an A chord in key of A major is I, a Bb would be ii, but it is a major chord.

I'm rusty on jazz harmony so I would greatly appreciate a helpful explanation and perhaps a guide to what to study jazz harmony like this further. I realize some might consider this a pop tune, but it sure seems like a tune with jazz harmony.

Answer 1

The first four bars go like this:

|Cmaj9 | Gmaj7 |Bbmaj9 | Fmaj7 | G | C/E| Asus | ...

with a melodic device in the first two bars on the G major scale that is repeated a whole tone lower (F major) in the next two (like the chords). So you have to see that chord as part of a sequence.

So what is happening here is that the melody starts in G major, with the chord sequence

IVmaj9 | Imaj7

then repeated in F major. In other words that Bbmaj9 is functioning as a IVmaj9 in F.

In general the song seems to have something of a "minor/major" character, where these excursions into keys that contain C natural and G natural (so use scales that sound related to A minor) then work their way back into A major. I don't know this song, but I'd hazard a guess that this device is repeated in the song, perhaps at multiple points.

Answer 2

If you wonder about the Bbmaj7 chord you should also wonder about all the other chords in the intro, because none of them is part of A major.

If you just listen to the intro (say, up to the G chord in bar 5), would you know that the song is in the key of A? My guess is that an honest answer would be 'no'. So it's pointless to analyze the intro in the key of A, because it simply isn't in A.

Apart from that, in standard jazz harmony the bII is a common chord that is borrowed from the phrygian mode. But in that Blood, Sweat & Tears song it is not used in that way.

In a classical context, that chord is called Neapolitan chord, but again, it is not used in that way in the song you ask about.

Answer 3

It appears this tune is in A Major.

I'm only guessing, but I think this is why you have trouble understanding what's happening. Perhaps you assume that because it's declared in the key signature, the entire song must be in a single key from beginning to end, and so you should be able to apply the same explanation patterns of simple functional harmony throughout the song?

In which key would you say this tune is "in"?

(I don't know where that came from but maybe it's a secret recording from a Pat Metheny Group cover band's rehearsal, an unpublished song maybe!? I think they should just keep playing covers if their original tunes are like that.)

What I'm saying is, particularly in jazz, you should treat each moment as potentially being in a different key. Jazz harmony often plays around with the feeling of changing tonal center and mode. Often the key signature does not reflect the entire song from beginning to end, and it may be a compromise that's chosen just to get the notation done, not to make any hard claims of the overall key. Otherwise they would have to write a key signature change or two for every bar. It would look awkward, and maybe it can be assumed that jazz players can tell where their home base is at each moment even without giving official recommendations all the time. :)

So, play the harmony and toy around with it. If you press "pause" at any given point, where would home be at that instant? How would you solo over it?

Answer 4

To me this song feels mostly like A-dorian, but using the major chord for the tonic. That's basically a Picardy third. But the main driving harmonic functional device is the slightly Irish-folksy ♭Ⅶ-Ⅰ, with the rather non-folksy twist that the ♭Ⅶ exploits the Dorian's ♯6 as its maj7 note.

Cmaj9 is simply the relative major of A-minor. The chords after it are, as danmcb said, part of the melodic sequence, and they're also connected by a chromatically descending line

X:1
L:1/1
M:C
K:A
%%score T1
V:T1           clef=treble
% 1
[V:T1] "C"=c | "G"B | "B♭"_B | "F"A

That line is rather hidden, but IMO it does already single out A as a target note, though it only feels properly home after the the pseudo/relative-dominant G brings us to an A proper chord.

Answer 5

I think, functionally, its behavior is closest to being a substitute dominant - a normal dominant Bb9 (with a A-flat=G-sharp rather than an A) would, after all, be the usual tritone substitution for E7.

The harmony for the whole song is very modal and not too functional though, so one should expect functional analysis to fall down a bit.