Jazz Chord Bass Chart
How to Couple Basses on the Stradella Bass Accordion
For stradella bass accordionists to achieve the more intricate chords represented in advanced chording, this chart below shows how to accomplish it by coupling various bass and chord combinations.
Below is an interval position chart for an accordion with 120 stradella basses is depicted. In this representation, the chords with their individual tones can be seen. Because for our purpose it is not the individual tones, but rather the pertinent intervals that are important, the intervals contained in the chords based on the root C are presented instead of the chord names.
In this way, you obtain a complete overview of the root (here C) and its relation to every extension chord button, and we can relatively easily gain an idea of the possibilities for combining (coupling) chords with one another and achieving approximately any given extension chord.
In the Key of G, just shift the entire chord numbering system up one row, in the key of D, up 2 rows, etc. It is easier to look for the desired chord in C harmony, play it on the accordion’s stradella bass manual, and then find it or its enharmonic substitution with the same finger position on the root bass.
Presented here are only intervals with an octave (with the exception of the ninth, inasmuch as the second does not play a role in chord symbols). For an eleventh, you should add the fourth; for a thirteenth the sixth, etc. Augmented/sharp fourth (#4) or eleventh (#11) corresponds here to the diminished/flatted fifth (b5). Diminished fifth (b6) or thirteenth (b13) corresponds to the augmented fifth (#5), etc.
Chart Link – Jazz Bass Positions Charts