Pitch Relationships
Senior 1 · Music
Pitch Relationships
Lesson 3 of 5
18 min
Two students look at the same black key: one calls it C♯ and the other D♭. Who is right? Both of them. In music, one sound can have more than one written name, just as one person can be called by a first name or a family name. Knowing both names, and when to use each, lets you read any piece and write music that others can read easily.
Notes that sound exactly the same but are written with different letter names are called enharmonic equivalents (or simply enharmonic notes). The black key between C and D is a semitone above C, so it is C♯; it is also a semitone below D, so it is D♭. C♯ and D♭ are enharmonic.
On the staff, enharmonic notes are written in different places, because they use different letters: C♯ sits on the C position and D♭ on the D position. But on the keyboard they are the same key.
The five black keys each have a sharp name and a flat name:
| Sharp name | C♯ | D♯ | F♯ | G♯ | A♯ |
|---|---|---|---|---|---|
| Flat name | D♭ | E♭ | G♭ | A♭ | B♭ |
White keys can have second names too, wherever there is no black key between two white keys. E♯ is a semitone above E, which is the key F, so E♯ = F. In the same way F♭ = E, B♯ = C and C♭ = B.
Worked example
Give the enharmonic equivalent of G♭. G♭ is one semitone below G: the black key between F and G. That key is also one semitone above F, so G♭ = F♯.
Worked example
What is the other name of B♯? B♯ is one semitone above B. There is no black key after B, so the next key up is the white key C. B♯ = C (the C just above that B).
Both names make the same sound, so the choice depends on what makes the music easiest to read. Two simple habits help:
On a keyboard, enharmonic notes are exactly equal. Unaccompanied singers and violinists sometimes tune them very slightly differently, but for your work, treat them as the same sound.
Tip
Same key, different letter. To find the partner of any sharp, name the key from the other side as a flat, and the reverse. The white-key pairs are the tricky ones: E♯ = F, F♭ = E, B♯ = C, C♭ = B.
Try each question first, then check the worked solution underneath.
Give the enharmonic equivalent of D♯.
Solution: E♭. The black key between D and E is a semitone above D and a semitone below E.
Give the enharmonic equivalent of A♭.
Solution: G♯. It is the black key between G and A.
Which white key is played for F♭?
Solution: E. F♭ is one semitone below F, and there is no black key between E and F.
Are C♯ and D♭ written on the same line or space of the staff?
Solution: No. C♯ uses the C position and D♭ uses the D position, one step higher. They only sound the same.
A melody rises from F through a black key to G. How is the black key usually written?
Solution: F♯, because the melody is rising.
Remember
Sources and credits
The lesson text, the notation and keyboard diagrams, the worked examples and the practice were written by Ganzaa.
This lesson adapts CC BY-SA material and is shared under CC BY-SA 4.0.
