When working with scores in keys of four sharps or more, it’s frequently desirable for transposing instruments such as Bb Clarinet or Trumpet to show their respective transpositions in flat keys. For instance, the key of B major concert (five sharps) will automatically display in Sibelius’ Bb Clarinet or Bb Trumpet staves as the key of Db (5 flats), rather than C# major (7 sharps).
This desirable behavior happens because “Respell remote key signatures in transposing score” in the Clefs and Key Signatures panel of the Engraving Rules is checked by default:
Sibelius’ rule for “Respell remote key signatures in transposing score” is: always show the enharmonic key signature which displays the fewest accidentals when transposed. For concert keys of five sharps or more, Bb transposing instruments will always show flat keys (which, coincidentally, many wind and brass players prefer).
However, you may have noticed that “Respell Remote Key Signatures” doesn’t work in four sharps concert, because, technically, the two possible enharmonic key signatures of six sharps or six flats, are equally “simple”.
That being the case, how can we coax a concert key signature of four sharps (E major or C# minor) to appear as six flats (rather than six sharps) for Bb instruments?
The secret is to create an enharmonic version of our Bb instrument which, when transposed, produces a key signature that triggers Sibelius’ “Respell remote key signatures in transposing score” feature. For the key of E major, an “A# Clarinet” will do the trick, yielding Gb major, rather than F# major.
To do this in Sibelius 7, select Edit Instruments from the Instruments Group of the Home Tab. In Sibelius 6, Edit Instruments is found in the House Style Menu.
If your Bb Instrument staff was already selected in the score, it will be selected in the Edit Instruments dialog. If not, find the Bb Instrument you want to create an enharmonic equivalent for.
With the instrument highlighted, click “New Instrument…”. You will be asked if you want to create a new instrument based on your currently selected one. Confirm.
When the dialog comes up, in the Name section, change the “Name in Dialogs” to, for instance, “Clarinet in A#”, so you can easily find in the list of instruments and apply it. Leave the name in score and other fields alone:
Now, in the “Transposition” section of the dialog, change the Transposing score note to A#:
It’s a little obscure, perhaps, but it works… :-) Anyway, now you know.
Since you have created this as a custom instrument, you can also incorporate it as an Instrument Change (at the same point as a key change) and in this way, control the individual key signature display for various different keys within the same piece.
Furthermore, since Instrument Definitions are saved as part of a House Style, if you end up creating an “ensemble” of these, you can save them off for later retrieval, so you don’t have to recreate these each time you need them.