Dissecting Smooth Jazz - Jingle Bells

As stated in my project brief, a large part of my ruleset creating involves listening to existing smooth jazz reharmonizations and dissecting them in order to access the gooey harmonies within.

Below is a version of Jingle Bells by Beegie Adair.

There are many, many, many added chords in this.  I've decided to focus on a few key chord changes and substitutions that I'll be using in my rulesets.

The verse of Jingle bells contains the following chord sequence in the key of F major:

F | Bb | Gm  | C7 | F | x 2

In the above video, the following sequence is played:

F Adim7/Eb Am D7 | Gm Dm G7 | C7 | F

Instead of a Bb an Adim7 is played with an Eb base.  This isn't a substitution I'd usually think of adding in, but it works with the melody.  The Abdim 7 chord features the 9th, 11th and 13th of the Bb chord, as well as the major third.  The Eb bass note descends to E, then D, etc.  Since I'm focusing on solo piano here, I'll stick to focusing on what the piano does.

If we think of scales rather than chords, the chord technically still resides within the Bb Ionian mode (or the Bb major scale).  Any root note within that scale could have been picked and it would have worked in some way.  The Eb works well with the melody of the tune.  

This means it may be possible to substitute any 4th chord (or any major chord for that matter, but for now we'll stick to the 4th) with with the "other" notes within the scale the chord in question is derived from.  Picking a root note depends simply on what the melody is doing.  This may prove trouble some when trying to create a one-size-fits-all rule, but it is something I can look at further down the line.

The chorus chords consist of

 F | (x 4) | Bb | F | G7 | C7 | F

In the track above, we can hear:

F x 3 | Adim7 D7b9 | Bb |

This is curious. Between the 1 and the 4 the player has added a minor ii-V in the key of the relative minor to the resolving chord (Gm).  Having tested this in different keys on other songs, a rule can be made out of this when going from a I chord to a IV chord.

The G7 in the chorus has also been replaced by a Gm7#9b5.  There are passing chords between the F and the G7, but the Gm7#ªb5 sticks out the most.  There is then little movement to go to the C9 chord preceding it (replacing the C7 chord).  

This is a basic description, but I'm starting to see ii-Vs - both major and minor) used everywhere.  There is a pattern emerging, and one that I seek to use.  ii-Vs can be placed almost anywhere, and then reharmonized themselves.  They can be altered, substituted or taken even further with the use of back cycling, which I'll talk about in a later post.

There are so many options for reharmonizing pieces - the difficulty is going to be in whittling the options down into rules.  Needless to say, my head is starting to hurt.

J