On choosing a two-row button accordion...

B/C is the usual choice for Irish music (players use both rows in order to play mainly in D or G, but the instrument is almost chromatic).

Is this right?

Why would you buy a B/C tuning to play D/G?

So why not just get one built in D or G?

  • B/C/C# is not an Irish traditional choice.. it is Scottish or English.. not Irish.
    – user30742
    Jul 4, 2016 at 1:27
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    There's a very good history of how the B/C box became the popular choice for Irish folk in an article on concertina.net titled "Irish Button Boxes". It elaborates on some of the answers given so far for this question. Feb 5, 2017 at 14:36

5 Answers 5


Because B and C are one semitone apart, you have access to every chromatic note, (and many notes twice) if you have both of those diatonic scales.

Melodeon notes

The top half of the diagram above shows which notes are available in the B and C diatonic scales, and whether you push or pull to get them. I'm not sure, but I think different octaves might have different push/pull patterns - the principle is right though.

So, with a B/C melodeon, you can play in any key at all, by using both rows. For some notes, you have a choice of whether to push on one button, or pull on a different button.

The bottom part of the diagram shows D and G. You can see that there are lots of notes absent. D/G melodeons either have this limitation, or work around it with a third row or some extra buttons.

That's the "how", but what about the "why"?

To play a D major scale on a B/C instrument, the push/pull pattern is:

Pull, either, push, push, pull, either, pull, pull

... and to play a G major scale:

Push, pull, either, push, pull, either, push, push

Accordion/melodeon music is typically very rhythmical, and the rhythm is hugely influenced by the push/pull pattern. There is a distinct slur when changing note without changing direction. There is a distinct stop when changing direction.

I suspect that the push/pull patterns when playing on one row aren't a great fit with traditional Irish music -- whereas a lot of English morris tunes sound just right with the stops and slurs where single-row play puts them.

The B/C tuning allows a choice of push/pull patterns, including patterns that fit well with Irish rhythms and melodies.

  • Slim, you are a veritable smorgasbord of musical knowledge. Apr 12, 2013 at 13:37
  • 1
    @gingerbreadboy if only I could play as well as I talk about playing...
    – slim
    Apr 12, 2013 at 14:09
  • This is a fantastic answer, in general. Thanks! ~ a keyboard squeezer who appreciates good button knowledge May 5, 2020 at 17:18

The D/G melodeon is a lot easier to play, but as already stated is really best for English (morris) dance music. The pull-push action of going up and down the scales give accent to the dancing.

The basses are a lot easier too. Most of the push and pull treble notes harmonise with the basses, and there is just one note really (E in G scale) which doesn't harmonise in this way; this is when you make the one change to the basses.

Sort of like the 3-chord trick on a guitar; you play the G basses until you "hear" the chord change coming up then change to C basses. It all harmonises.

You can use the same method when playing in the key of C on a B/C box; play the C basses until it you hear the chord change coming then change to the F basses.

Most Irish music appears in the violin keys of G and D, so when you start a scale on the B/C box other than key of C you can't use the basses this way. The basses you have are (push/pull) G/D, C/G, E/A and F/F. It is most common to retune the push F to a D.

When you play a tune in D or G you simply play the same (or harmonising) bass as the treble on the first beat of the bar. ie. if you play an A on the treble, you play an A bass. If you play a F# on the treble you play a D bass.

Many Irish box players don't play the basses at all and project the rhythm through ornamentation.

The layout of the B/C rows makes it easy to make semi-tone cuts and to emulate the rolls that you hear on a fiddle. Despite what other people may say you simply cannot express Irish music as well on a D/G melodeon.

When going up the scale of D on a D/G melodeon you only have two notes next to each other where the bellows are played the same direction: B and C#. On a B/C box you can travel up from A, B, C#, D, E all on the pull action. This allows for the fast and smooth runs required in certain hornpipes.

The other big plus of the B/C box is that it is fully chromatic and all sharps and flats are right under your fingers. Much of Irish music is modal and you will need these extra notes.

If you want to play Irish music I would recommend the B/C for these reasons.


When you're in the key of C, you can also play in D dorian, F lydian, G mixolydian, etc. So each 'key' is actually very flexible. Also if we constrained ourselves to the major pentatonic scale, you will see that an instrument in C can perfectly well play in C, F, and G. Or with minor pentatonics, that same C instrument can play in d, e, and a.

Pretty flexible! With just two instruments of different key you would have access to most keys you would ever want to play in.


Actually, the most popular tuning these days is the C/C# box or even a C#/D The layout of a C/C# allows superior ornamentation and fewer bellows changes. When I started playing my B/C, I looked for a teacher here and was told nobody plays B/C. Then there are the Irish 3-row boxes that are B/C/C#

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    John Fine, where are you based? I'm really not sure that your comment is objectively true. I play in sessions a lot and I almost ever come across B/C accordions. Sep 25, 2016 at 12:26

The notes B and E are in both directions so, depending on the chord youre after ie Em or Am you'll play the appropriate one. This takes a bit of getting used to. Using two, three or four fingers on the left is a subject for debate as is the question of using your pinky on your right. Plenty of variables to keep you amused through the cold winter's nights.

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