Key-Signatures With 7-Flats Or 7-Sharps

In using the “Transpose” button, you may have noticed there is no entry for “7-flats”, or “7-sharps”. Neither are there entries for “C-flat Major” and “C-sharp Major”, nor “A-flat Minor” and “A-sharp Minor”.

It’s even less likely you’ve seen a piece of music written in any of these key-signatures, though it is actually possible.

So if you actually do run into a piece with a key-signature having 7 flats, or 7 sharps, how do you play it on the KMK, and why doesn’t the KMK support it like all the other key-signatures?

The reason key-signatures with 7 flats or 7 sharps are not directly supported, is because the KMK handles the various key-signatures by transposing.

Notice in the screen-shot of the “Set Transpose-Interval / Key-Signature” below, there is a negative or positive number at the left of each of the first four drop-lists (the ones specifying the key-signature):


That number (1-Down, or minus 1), specifies how many half-steps (semi-tones) notes or chords are transposed. A negative number (such as -1) means transposed down, while a positive number (such as +1) means transposed up. The number 0 means no transposition is done.

A ‘C-flat’, is actually 1 half-step (semitone) down from C, which is actually a B, as shown in the screenshot below:


KMK Music Display, Showing A C-Flat Being Played

Notice the note-head of the note played, is on the middle-C line, with a flat-sign to the left of it. The note marked in the piano-keyboard diagram, has the note-name “B”. A ‘C-flat’, is actually a ‘B’.

If we select the key-signature 1 semitone down (1-Down) from the default key of C, we get the key of B-major, as shown in the screenshot below:


This is also (as shown in the 2nd and 4th drop-lists in the screenshot above) a key-signature with “5-sharps”, and the key of “G-sharp Minor”.

So when we select that key-signature, we get a key-signature with 5-sharps, as shown in the screenshot below:


Here, I’m pressing the Q-key of the typing-keyboard, which plays a C-note on the piano keyboard diagram (shown by the right column of note-names), which transposes to the B-note in the target key-signature (shown by the left column of note-names).

The key of ‘B’ (5 sharps) sounds exactly the same as the key of ‘C-flat’ (7 flats). They are only different in how they are written in music notation.

In designing the KeyMusician Keyboard, the reasoning was: “Why would you write a piece in 7-flats, when you could more simply write the very same music in 5-sharps?”

The very same thing applies to the key-signature of C-sharp (7-sharps). It is tonally identical to the key of D-flat (5-flats).

The key-signatures of 7-flats, and 7-sharps, were not included, because you can play the very same music, by setting the key-signature to 5-sharps (in place of 7-flats), or 5-flats (in place of 7-sharps). End of story, or so it seemed.

I found out years later, that there are very rare cases, where a key-signature of 7-flats, or 7-sharps, might actually be used.

I noticed in writing an orchestra score for a piece in the key of B (5 sharps), the part for a B-flat clarinet, or a B-flat trumpet, requiring 2 additional sharps) will use the key of C-sharp (7-sharps). At least, the MuseScore application, which I use for writing orchestral music, does it that way. Other scoring tools might possibly do it differently.

Also, when I orchestrated Brahms’ piano sonata in F-minor, I noticed a section where Brahms used the key of A-flat minor (7-flats). He didn’t do it by changing the key-signature, instead, he simply wrote a flat-sign in front of every note of that section of the piece.

I attempted to enhance the KMK’s code to allow these two additional key-signatures, but in the case of these two key-signatures, no transposition is done, but rather, every note played (or root-chord note played, in addition to slash-chord note played), is flatted (for the key of C-flat) or sharped (for the key of C-sharp).

But does it matter? Just set the key-signature to ‘B’ for ‘C-flat’, or ‘D-flat’ for ‘C-sharp’, and play the piece.

That kind of works, but if you’re trying to match the position of the note head, to the position of the note-head in the music, some of the notes will be wrong.

For example, look at the position of the note-head in the two screen-shots below, for playing the C-flat note:




Here, the note-head for playing the C-flat note, should be on the ledger line between the bass and treble clefs. But in the key of B, it’s in the space below that ledger line. Some note-head positions in the key of B, differ from the note-head positions in the key of C-flat.

Fortunately, when using a typing-keyboard (rather than a MIDI keyboard), there is a way of playing the KMK in key-signatures having 7-flats, or 7-sharps, without having to transpose to their tonally-equivalent key-signatures (5-sharps, or 5-flats). It’s a bit awkward, but it works.

Simply set the key-signature to no flats or sharps (key of C), and place a lead weight on the left shift-key (for 7-flats), or on the right shift-key (for 7-sharps). You can even put the weight on the laptop keyboard, while you play on a USB keyboard. It will work either way.

You won’t see the 7-flats, or 7-sharps in the key-signature, but instead, a flat-sign (or sharp-sign) will be put to the left of every note you play, since every note is an accidental (a note not in the key-signature’s scale). And all of the note-head positions will be correct.

You can convince yourself of this (without having a lead weight), by holding down the left shift-key or right shift-key, while playing notes. Every note will be flatted (in the case of the left shift-key), or sharped (in the case of the right shift-key).

This trick even works for the chords you play on the numeric keypad.

Every chord you select, will be flatted (with the left shift-key), or sharped (with the right shift-key). And any slash-chord note you select, will be flatted or sharped in a similar manner. Check out the Chords window screenshots below, as examples of this:




In the left screenshot, I selected a C-flat major chord. In the right screenshot, I selected an F-flat major slash D-flat chord (you could also call it F-flat major over D-flat). This trick only works when playing music on a typing-keyboard, and/or playing chords on a typing keyboard.

If you’re using a MIDI-keyboard, your best bet is to set the key-signature to ‘B’ (for the key of ‘C-flat’), or ‘D-flat’ (for the key of ‘C-sharp’), ignoring the note-head positions that don’t match. You could also learn to play in those key-signatures, playing all the flats or sharps manually, but you shouldn’t have to do it the hard way.

This is necessary because on a MIDI keyboard, you play accidentals by playing the black-key above, or below the white-key note, rather than having to mess with the shift-keys (or Page-Up and Page-Down keys) of the typing-keyboard. You play everything in the key of C (or A minor), depending on the transpose to play in the target key-signature.

Here’s a picture of me playing the KMK, using a weight on the right-shift key, which yields the key-signature of C-sharp major:


In this case, the weight (laying on the right-shift key, between my hands), consists of a short bolt, with multiple nuts.

Here’s a close-up of the screen, while playing it:


Notice in the “Keyboard Monitor” window, I’m pressing the E-key, and the right-shift key is pressed (because of the weight). My thumb is holding down the numeric keypad 0-key (the “Play” key).

Notice in the music display portion of the main window, the E-note I’m playing has a sharp-sign in front of it. Also notice, in the Chords window, I’m playing an F-sharp major-7th slash D-sharp chord.

The up or down arrow symbol in the chord buttons, is used because of limited space in the chord selection buttons. Up-arrow means ‘sharped’, and down-arrow means ‘flatted’.



I hope this trick proves useful, if sometime in the future, you run into the very rare case, where you have to play a piece written in a key-signature of 7-flats, or 7-sharps.

You can see the index of all newsletter articles by following the link below.

Index Of All Newsletter Articles