What chords can be played on an accordion?

Question

I've looked into how an accordion works and I want to play one in the music school. A piano accordion with 6 rows of buttons on the left hand, to be precise.

Now, I've been brainstorming about playing some songs and I wonder if some special chords might be playable on the accordion with the left hand. I know that there can be major, minor, dominant 7 and diminished, but I'm wondering about something else. Here are my chords:

(Note: English is not my main language so most of the things regarding music will have a big language barrier. Please help me correct my terminology.)

In Eb major and C minor key:
BASS: Bb; CHORD: Bb Eb (F)G  - Sustained 64 (from classical harmony) on Bb major
BASS: F ; CHORD: F  Ab C  Eb - F minor minor 7 with
BASS: F ; CHORD: F  Ab (C)D  - 2nd inversion of D diminished optionally mixed with F minor
BASS: Ab; CHORD: F  Ab Bb D  - 2nd inversion of Bb dominant 7
BASS: Eb; CHORD: Bb D  Eb G  - 2nd inversion of Eb major major 7
BASS: D ; CHORD: D  F  G  B  - 2nd inversion of G dominant 7
BASS: C ; CHORD: C  D  Eb G  - C minor with an extra major 9th
BASS: D ; CHORD: G  B  Eb    - 1st inversion of Eb augmented

Do you know if these chords can be played only with the left hand while the right hand plays a melody?

Answer 1

Generally, the accordion standard bass is rather uninterested in inversions, less so than even the guitar. In almost all registrations, the respective chord notes sound in several octaves simultaneously and the chosen inversion is not determined by the player but by the layout of the chord reed banks.

The chords are "grounded" by playing an appropriate bass note (usually in an accompaniment pattern that alternates between bass notes and chords).

So basically forget about inversions: you get to choose your bass notes, but the chords have a fixed inversion and the octaves of both bass note and chord are determined by the registration and the reed bank layout and are usually rather fuzzy through the use of multiple octaves. Bass notes are usually coupled into both bass and chord reed banks, making their octave relation even fuzzier. Mostly Italian instruments may even have different octave breaks for different reed banks: an Excelsior I have here starts octaves in the bass at A1 and A2, and in the chords with F#3, C4, C5 so if you register "Master", scales in the bass (which use all reed banks) have several different octave breaks in the result.

Apart from that, chord buttons may be combined. This is helped by diminuished chords never having a fifth, and by seventh chords almost never having a fifth (with the exception of some older mostly German instruments).

Since many jazz chords are actually "stacked" triads, one can often play them using two buttons (exception: suspended chords which you can only approximate by deliberately tolerating some non-chord notes).

For example c+em yields cmaj7, c+am yields am7, c+gm yields c9, and so on. Of course, once you stack chords, the "no inversions, single octave" deal of the standard bass becomes more of a nuisance and it becomes more important to "ground" the chords with suitable bass notes. It is sufficient to alternate them with the resulting complex chords: this is less mushy than playing all of once, needs less air, sounds more interesting and the result is psychoacoustically still rather firmly connected to the bass note.

Answer 2

Here a like to the usual Stradella layout for a piano accordion (and the bass of many button accordions.) https://en.wikipedia.org/wiki/Stradella_bass_system

The columns go by fifths up (and thus fourths down). The bass rows are simple. The fifth row is the bass line. There is a indentation on the C bass button. The sixth row is a major third above the bass row, so that button plays an E. The next column up has a G and a B and the next column down has an F and an A respectively in the fifth and sixth rows.

The chords are a bit more complex. The fourth row the major chord with root in the bass, so C,E,G for the C column. The next row is the associated minor chord is C,Eb,G.

The second row is called the dominant seventh row; it is the dominant seventh with the fifth missing (so it's an Italian sixth in another key.) For the C row the notes are C,E,Bb (it the Italian sixth for E-major or E-minor). The first row is the diminished seventh chord with the fifth missing, C,Eb,A.

The fifths are omitted for two reasons (suggested by Stradella so the layout got his name): first, all chords have three notes and the weight between the tones are balanced, and second, one gets the augmented sixth chords easily.

What I do is play the chord of interest and sometimes add missing things (like ninths or sixths) in the right hand below the melody.

Answer 3

I use this page to find out how to get some fancy chords from a standard bass accordion: https://accordionchords.com/all-chords/

You can find chords charts for all these chords:

• 6th
• 7b5
• 7b9
• 7th
• 9/11
• 9th
• Dim
• min6
• Maj7
• Maj7/9
• Major
• min(Maj9)
• min7
• min7b5
• min9
• Minor