Variations on the 2 ½ Row Diatonic Keyboard
Typical 23+4
This configuration shares the treble layout of a standard 23 button melodeon with 4 additional buttons on the inside row. It slightly favors playing tunes in G over tunes in D. It is fully chromatic through 1 octave on the pull. The half row has a pull reversal for E (the aeolian and dorian tonic) , as well as accidentals. The extra 4 basses are set up as for a standard 3 row - namely to work with the key of A, but in spite of that, the treble seems better suited to play in the key of C (most especially in aeolian mode, A minor), so some potential benefits are not fully realized since the bass and treble aren't in sync in that regard.
23+4 D/G
Andy Cutting's 21+5
This is the layout used by Andy Cutting on his 21+5 instrument. It is a well thought out system which has more to offer than the 23+4 system above, in spite of the fact that Cutting's system has 1 button less. Cutting's system strives less for chromaticism and more for optimizing the main keys of the accordion, D and G. The keys of D and G can be played entirely on the pull through 2 full octaves, as can C and F for that matter. The low notes are used to continue the scale downward, allowing a complete D scale to the G below low D. The half row gives 3 useful reversals as well as 4 accidentals. This system is fairly equally balanced for play in the keys of D and G, except that mixolydian tunes are often much easier to play in D (relative to G major). When playing outside the home keys, this layout definitely favors the key of C over the key of A. The 12 basses stay fairly close to home, all being common chords for D and G plus C and A. One difference to be noted from the standard 8 bass is that the B chord is minor rather than the more normal major. This matches the treble well, but somewhat weakens the key of E minor while strengthening the the key of B minor (which is relative to D major). The logic of the bass side seems to indicate that a stop to remove the thirds from the basses is optional, because when pulling the 3rds, the pull A chord is duplicated. Theory aside, Andy Cutting uses this layout to great effect. .
Andy Cutting's 21+5 D/G
Hohner Club 23+7
This is the venerable, time tested 2 1/2 row layout first introduced by Hohner on its Club models. It is also the largest treble layout of the 2+ row systems we are looking at on this page, weighing in at 30 buttons - a full 3 buttons more than the next biggest system. In spite of its number of buttons, I don't feel it is any more powerful than some of the smaller systems, such as Andy Cutting's which we have already discussed. The reasons for this may become more apparent as we get into the analysis. Like the 23 button systems, the tonic button is the 4th button rather than the third. The treble is fully chromatic through 1 octave on the pull, but the chromatic range grows to 3 octaves if bellows reversals are used. The key of G can also be played completely on the push. The system favors playing in the key of G in all modes. The key of C is also favored compared to the key of A in all modes. Disregarding the bass, the instrument can play in any key with a 3 octave range. So far, all is positive for the Club. However, a major weakness comes when looking at the bass system. During the design of the Club, it seems the bass was neglected, which has led to it being considered more of a treble instrument with some limited bass support. The Club system normally comes with only 8 basses. They are set up as a normal system with the exception of the C chord which, rather than being unisonorous as normal, has the same 5th apart binsonorous relationship all the rest of the bass buttons have....namely it give an F major on the push (which allows the basses to fully support the key of C). This is moderately useful, but not enough to balance the power of the bass with the treble. So the bass system is a major weakness. The other major weakness is the non-standard layout of the 2 home rows of the treble, which departs from the normal "protected" 19 button core in two places. Button number 12 on the outside row and button number 6 on the inside row. In both cases, the normal note is replaced with a pull reversal of the D note. Although button number 12 is not very bothersome for most players, button number 6 forces cross row playing in the middle of the instrument, requiring experienced players of standard boxes to relearn their fingering patterns.
Hohner Club 23+7 D/G
Bernard Loffet's Pro 21+6
Although Bernard doesn't take credit for inventing this system, it is through his instruments that I became aware of it, thus for lack of more complete knowledge of the originator, I have named it in his honor. At 27 treble buttons, this is by far the most powerful overall of the systems yet considered. The Loffet system is broader in outlook compared to the Cutting layout, meaning that it is intended to do everything at least moderately well, whereas the Cutting system is intended to further optimize the strengths of the standard 2 row (its improvements being very focused, rather than general). As a result Cutting's system is slightly more powerful in the keys of D and G and their immediate neighbors C and A, but the Loffet is more powerful everywhere else by quite a bit. It is fully chromatic through 2 octaves. In addition, the keys of C, G, D, and A can all be played completely on the pull. The key of G is favored for all modes except the dorian. The core 19 are standard, but the low notes are utilized to continue the diatonic scale to the A below low D in both the keys of D and G. The half row is logically and conveniently setup to offer the accidentals in reversed fashion from the standard, as well as reversals in two octaves of the D and E buttons, both quite important tonics for various common modes. The 12 basses match the treble very well with one exception, namely the A# chord. The extra 4 basses do not stick close to home, but rather attempt to cover as many "accidental" chords as possible. In normal play, these extra basses won't see much action, so perhaps some players might benefit from altering these to perform more useful functions. The Loffet's bass system benefits (much more so than any other so far) from a stop to silence the 3rds in the chords.
Bernard Loffet's 21+6 D/G
Karel Van Der Leeuw's 20+4
So far, all the systems we have looked have been derived from the standard 2 row layout. This one, by noted Dutch accordion builder Karel Van Der Leeuw, is an example of a 2+ row system which is derived from the Dutch standard 2 row. Of all the layouts on this page, this one is the most efficient (not powerful, efficient), but it has some drawbacks which will be enumerated further on. Notably, this is the smallest layout, at only 24 buttons....that's only 3 buttons more than a standard layout, and only 1 button more than a 23 button 2 row! Like most of these systems, it favors playing in the key of G in all modes, and is better in the key of C than the key of A. Like the Cutting system, the improvements introduced by Van Der Leeuw are focused on the keys of C, G, D, and A, rather than the whole spectrum of keys. It is fully chromatic on the pull through 1 octave and the keys of G and C can be played entirely on the push or pull in one octave. The keys of D and A can be played entirely on the pull in 1 octave. Unlike Cutting's system, all accidentals are present, though A# only appears once. The 11 basses are set up in a fashion to eliminate the need for a 3rd stop. Like the Club system, the C bass has an F major reversal. The upper row of chords is augmented by supplemental chord buttons of the same tonic but in alternate major or minor keys so that all 4 of the top chord buttons is playable in full major or minor configuration. In addition, 2 supplemental buttons are inserted for accidental fundamentals. Personally, I think that these would be better placed below the G major chords. Speaking now of the disadvantages of this system, they are significant. First, 20+4 is an uncommon configuration for a button accordion, and as far as I know it is only manufactured by Van Der Leeuw. Since the outside row is short 1 button, the D scale starts on the 2nd button rather than the 3rd. Button 10 on the outside row is also totally non-standard, in effect there are only 9 standard buttons on the outside row. On the inside row, the scale starts on the 3rd button as normal, but buttons 2, 5 and 8 are non-standard. This results in a need for total relearning of the fingering. These buttons have been appropriated to provide reversals and eliminate duplications. Thus the efficiency of the system. Furthermore, the 11 basses are non-standard. I like the setup of the system, but with 1 more bass button, 2 more fundamentals could be added resulting in 11 of the 12 possible bass notes being available for use. Locating these fundamentals below the regular basses would also maintain the standard bass fingerings.
Karel Van Der Leeuw's 20+4 D/G
