Reimagining the Stradella Bass

The Stradella bass system is extraordinarily efficient, provided that the music you want to play behaves itself. Its major, minor, seventh and diminished chord rows offer instant functional harmony, but each button gives you a complete chord chosen in advance. That becomes restrictive when playing music built around drones, open fifths, modal ambiguity and moving inner voices.

I began wondering what would happen if a four-row Stradella system were reduced to its harmonic components.

The instrument would retain its counterbass and fundamental bass rows. Of the two chord rows, the major row would lose its thirds, while the minor row would lose its roots.

For each nominal chord, the rows would therefore contain:

The third row would become a row of bare fifths. The fourth would become a row of major-third intervals, although each would retain the name and mechanical position of the minor chord from which it came.

For brevity, I shall call these the fifth row and the partial row.

(I should add, there is precedent here. My good friend Murray Grainger removed the thirds and sevenths from his dominant seventh row to allow for bare fifths, yet also retain dominant sevenths by cross fingering to the half diminished row. The Grainger Bass system is also used by several other prominent accordionists, most notably, Paul Hutchinson. However, I'm looking at a much smaller instrument that has neither dominant 7th nor half diminished rows.)

The basic harmony

The simplest combination is also the most obvious:

C–G + E♭–G = C–E♭–G

Pressing both chord buttons in the C column reconstructs C minor. Alternatively, playing the C bass with the E♭–G partial produces the same chord with less duplication.

Major harmony initially appears more difficult. To construct C major from the two chord rows, the missing E natural comes from the modified A-minor button:

• C fifth: C–G
• A partial: C–E
• Combined: C–E–G

Because A lies three positions away from C on the Stradella circle, this is possible but not especially convenient. It might suggest that the fourth row should be displaced mechanically to bring the necessary partial closer.

That turns out to be unnecessary, because the unshifted arrangement has a more interesting harmonic logic.

Major chords hiding inside the partial row

The C partial contains E♭–G. Those are the root and third of E♭ major.

Add a B♭ bass and the result is:

B♭ + E♭–G = E♭ major in second inversion

Add the complete B♭ fifth instead:

B♭–F + E♭–G = E♭–G–B♭–F

This is E♭add9/B♭.

The relationship transposes consistently:

These combinations are only two Stradella positions apart. They fall naturally beneath the hand and produce the open, unresolved major sonorities that suit traditional and modal music particularly well.

The system therefore does not merely recover the major and minor chords removed during modification. It provides several alternative versions of them.

Pairing two fifths

Two neighbouring fifth buttons produce suspended chords.

Using C as the reference:

A movement of one position creates a suspended triad. A movement of two creates either a modal dominant seventh or an open sixth/ninth chord.

Because none of these chords contains a third, they can accompany melodies without prematurely deciding whether the music is major or minor.

Pairing two partials

The partial row behaves differently. Neighbouring buttons often complete major-seventh chords.

The C partial contains E♭–G:

One-position movements produce complete major-seventh chords. Two-position movements produce compact dominant-ninth structures.

This is a considerable return from a row containing only two sounding notes per button.

Pairing fifths with partials

Mixed pairings provide the broadest range of colours:

Chord names are inevitably dependent upon context and the chosen bass note. That ambiguity is part of the system’s value. The same collection of notes can change function beneath a moving bass or melody.

The counterbass row

The counterbass row becomes more useful because it can supply thirds omitted from the fifth row.

The C fifth gives C–G. The E counterbass in the same column supplies the missing major third:

E + C–G = C major/E (first inversion)

The F-column counterbass gives A. Played against C–G, it produces A–C–G, which may be heard as Am7 without its fifth.

More unusual harmonies are also available. The C partial gives E♭–G, while the counterbass in the G column gives B. Together they produce G–B–E♭, an enharmonically spelled G augmented triad.

The counterbass row is no longer merely an alternative source of bass notes. It becomes a chromatic colour row.

The resulting vocabulary

Within a reach of two Stradella positions, the modified system provides:

• Major and minor triads
• Open fifths
• Augmented triads
• Suspended seconds and fourths
• Major sevenths
• Dominant sevenths without thirds
• Dominant ninths
• Add9 chords
• Minor sevenths without fifths
• Open 6/9 chords
• Suspended flat-nine chords
• Major-seventh and add9 inversions

The principal omission is the instant root-position major chord. That requires either the appropriate counterbass note or a three-position pairing between a fifth and the partial derived from its relative minor.

For conventional oom-pah accompaniment, this would plainly be less convenient than ordinary Stradella. That is not its intended purpose.

Its natural vocabulary consists of bare fifths, suspended harmony, major sevenths, inverted major chords, minor triads and open added-note sonorities. These are precisely the harmonies that conventional Stradella often makes unnecessarily difficult.

The mechanical alteration

On a conventional three-note chord mechanism, the required changes are conceptually simple:

• Remove the major-third engagement from every major-chord lever.
• Remove the root engagement from every minor-chord lever.

Thus the C-major lever loses E and retains C–G. The C-minor lever loses C and retains E♭–G.

The physical position of the relevant pins varies between bass mechanisms, so they must be identified by tracing which note slide or pallet each pin operates. I would test the design through reversible disengagement before cutting any lever permanently.

A different harmonic instrument

The resulting instrument should not be seen simply as a Stradella system with some notes missing. This is a left-hand system organised around intervals rather than predetermined chord qualities.

Its grammar is beautifully economical:

• The same column gives a minor chord.
• Adjacent fifths give suspended chords.
• Adjacent partials give major sevenths.
• Two-position fifth pairings give modal sevenths and open 6/9 chords.
• Two-position mixed pairings give add9 and ninth harmonies.
• The counterbass row supplies major thirds and altered colours.

This system supplies considerably more harmonic freedom than a conventional Stradella layout.