Music theory reminder
The key signature enables you to define, within
a score, a change of tonality, i.e. which scale is
used to play the
Here is the list of all notes which can be played
within an octave:
Each of these notes is a semitone lower than
the next one.
A major scale has seven notes, with irregular
intervals between them: from the root note of the
scale, the notes
are located at semitones +2, +4, +5, +7, +9 and +11,
which gives, for
C major scale, semitones 1, 3, 5, 6, 8, 10, 12, i.e.
the scale C, D, E,
F, G, A, B.
For the D major scale, that sequence of intervals
made of semitones 3 (root note), 5, 7, 8, 10, 12
and 14. Semitone #14
is in fact the 2nd semitone of
the next higher octave.
Thus, it gives the D major scale: D, E, F#, G, A,
In a score, if only the notes belonging
to the scale of D are used, then all Fs and all Cs
sharped. To make the notation less cluttered,
sharp symbols are drawn only once, just after the
This informs the performer
of the key being used, and in
so doing, the default
accidentals (notes with sharps or flats).
To determine which key is used in a score (or
a part), just count the number of sharps or flats
drawn after the clef:
|Number of sharps
||Number of flats
The group of these signs placed after the clef
the key signature.
Generally, key signature changes apply to all
staves in the score. Some instruments such as the
trumpet or horn do not play the note actually
indicated on the score,
but a note shifted up or down by a given number of
They are called "transposing
In the software, to define a staff
for a transposing
instrument, use "Staff>Apply
transposing instrument" or the
transposing instrument" in the
staff contextual menu .
For example, on the staff for soprano clarinet,
notes are played two semitones below the note
actually written .
If the note C is written in the score, the clarinet
thus plays a Bb. It is a Bb transposing instrument.
To make a clarinet play an ascending scale of
C, i.e. the notes C, D, E, F, G, A, B, you must
write D, E, F#, G, A B,
C#, i.e. a D major scale.
If the whole score is in the key of C major,
i.e. with no key signature, the clarinet staff will
have a key
with two sharps, as if it were in the key of D
The software extends the notion of
instrument to any instrument which
does not play the note exactly as
Thus, instruments like the piccolo
or bass, which
are not strictly speaking
transposing instruments because
the written note shifted by a
given number of octaves, are
the same option.
A key change is always positioned at the
of a bar.You can specify a change of key signature
at any bar in the
For example, a staff can begin in the key of
C major, and then switch to F major a few bars
To change the global
key signature of a score, select "Score>key and
The key signature selection box opens.
A dedicated tool palette ("Window>Clef &
signature tools") is available. It contains the
key signature change
as well as tools for changing
Select the key signature change tool (icon
with sharp symbols on a staff) and click on a
bar. The key signature
Selecting a key signature
In the selection box, choose the "key signature"
tab. In the upper portion of the window, you can
see a preview of the key signature you are
By using the scroll bar you can add sharps and
flats to, or subtract them from, the current key
can also define custom keys by using buttons on
the right, and defining
the root note in the bottom field.
The "visible key signature" check box
to define whether the key signature is displayed
or not. To
ensure that your score remains readable, however,
The key signature display
mode defines whether natural symbols are
used to cancel the
key signature or not.
The Propagate change till the end of tune check
enables you to transpose all key changes following
the one you are
setting. For example, if you switch key signature
from C to D, all
key signatures will be increased by two semitones.
In that case a G key
signature (one sharp) later in the tune will be
transformed into A
At the bottom of the window, pop-up menus enable
you to select:
• The transposition to apply to
notes when a new key is inserted into a score.
Notes following this key change can be:
• Which staves the key signature will be
Not transposed: in this case, their screen
changes so that they play the same pitch as
Transposed up: they will play in the new key,
a higher pitch than before.
Transposed down: they will play in the new
at a lower pitch than before.
Graphically unchanged: they will stay at the
graphical location on the staff (but they may
not sound at the same
It can be the current
staff only, all staves in the score, or only
In the two last cases, you can select whether
the change is made in absolute or relative mode.
In absolute mode, the key change is applied as-is
to other staves.
In relative mode, the key change is applied taking
into account any key difference between the two
staves (due to
transposing instruments). See below for more
information. In case
select relative mode.
Absolute and relative mode
As described above, a key change can be applied
When applied absolutely:
The new key change is inserted "as is" in all
the required staves, i.e. all staves will play the
same key at the same
time. This is the general case for all pieces of
music, except when
transposing instruments. Key signatures for these
shifted a given number of semitones from the
regular key. Because of
applying the same key signature to all staves,
including those playing
transposing instruments, will result in erroneous
keys for these
When applied relatively:
The program calculates the difference in semitones
between the root note of the current key (at the
location you clicked
and the new key you want to insert. This
difference is then applied to
the key signature at this bar for all required
key offset is then kept.
For example, if you
have a first staff with a D key signature and
another staff in G;
an E key signature
in relative mode on the first staff will result
- The difference between old and new keys is
E-D = 2 semitones
Be careful, however: if you use custom keys, the
program is not able to shift them
up or down (it is impossible to determine
whether accidentals must be added, or where). If
such key signatures
present in your score, only their root note will
be transposed as
and the accidentals will not be changed.
- The first staff key is raised by two
semitones: D+2 semitones = E as
- The second staff key is raised by two
semitones: G+2 semitones = A
||In summary: It is not
recommended to use absolute
change mode on staves
playing a transposing
On the other hand, relative
mode will not calculate
new accidentals for existing custom