Why do black keys on a piano have 2 names?



I’m a complete novice to music and am learning piano, I just bought some stickers with the notes and letters for my keys but the black keys have 2 notes and letters, do they make a different sound when you hit them higher up vs lower on the key?

In: Other

You’re referring to sharp (#) and flat (b). Its the same note. Think of it as halfway between two natural notes. A# (sharp) is the same as B b(flat)

Nope, it’s the same note with the same sound, whether you’re playing a D sharp or an E flat. (The two names are called ‘enharmonic equivalents.’) It’s a pitch exactly halfway between D and E.

The note has different names because it belongs to a number of different scales, and it plays different roles in each of them. In the C minor scale, you call it E flat because there’s already a D natural in the scale and the next note is F, and the rule is that each letter is used once. E goes between D and F, so it’s E flat.

So the musical alphabet is made up of the letters A-G. the white keys on the keyboard represent these letters. The black keys represent the “sharps” (#) and “flats” (b) that occupy the notes in-between. For all intents and purposes, the black keys do have 2 names due to the two white keys that surround it. For example, the black key to the right of the white C key and to the left of the white D key can be called “C sharp” or “D flat”.

To answer your second question, no; the black keys make the same note no matter where you actually hit the key. I hope that helps.

The note it makes has two names. You could be making a C higher pitch and getting a sharp C, or you might be trying to make a D lower pitch and getting a flat D. It’s useful to think of it that way, by what you are trying to change but the secret is that a higher pitch C and a lower pitch D are both the exact same sound so you get one key that does both but is nice enough to mention either name works.

Black keys on a piano are half a tone higher/lower than the white keys next to them. They should sound the same wherever you hit them, because it is the same note throughout the black key.

While they have two different names, they are still the same note – the different names are used depending on the context. So C# and Db are the same note.

The black keys are typically used in different scales – C major is the scale that most beginners use, as it has no sharps or flats and only uses white keys. G major has one sharp (F#), and F major has one flat (Bb). If you want to learn more about scales, I suggest looking up the circle of fifths.

Hope this helps 🙂

There’s a term for it: enharmonics. From my own basic grasp of theory: It has to do with key signatures. Key signatures tell you which flats and sharps to play in a given piece. (For our basic purposes, these are the black keys on your piano. They are a half step in tone above or below what we call a natural, which is a note like C or D.)

For instance, the key of B flat major tells you to play two flats whenever you see a B or E in the song: B flat and E flat. The key of E major, however, has four sharps. One of them is D sharp, which is the enharmonic equivalent to E flat. By calling it D sharp instead, it fits in with the other sharp notes. It’s neater and easier to read.

Check out the circle of fifths. This should help you visualize it better. https://medium.com/@musicintervaltheory/what-is-the-circle-of-fifths-in-music-theory-85e1b29b0f6a

I hope that helps. Theory experts, feel free to correct me of course.

Is there an instrument where C# and Db would be a different sound?

It is like the english words to, too, and two. They all sound the same but mean different things. A C# would be the major 3rd of an A major chord. A Db would be the sus 4 of an Ab sus chord. FYI all the white keys on a piano can also be called by a sharp or flat name. Even double sharps and double flats. It is all to keep the spelling correct in music notation. C# and Db sound the same but are notated differently depending on the context.

They make the same note. That note has different names depending on context. Primarily it depends on the key you are in and if the musical line is going up or down.

C# and Db (two names for the black note in between the C and D white notes) are not necessarily the same thing. One (Db) is a minor second *above* C, the other (C#) is a minor second *below* D.

In the typical tuning for modern instruments in the West – twelve-tone equal temperament – the two happen to correspond to the same frequency. But in other tuning systems, they don’t.

If you tune an instrument to a specific key (“just intonation”), the sound of each note is defined by ratios of the key note (“tonic”)’s frequency. If, for example, your key is C, then you define other notes as ratios of the frequency of C. For example, the perfect fifth of the key of C (which happens to be G) is tuned to 3/2 the frequency of C. In just intonation, the minor second – in this case, Db – is 16/15s the base frequency, or 1.0666… times the base frequency. C#, on the other hand, doesn’t exist in the key of C, and its frequency depends on what key it *is* tuned to – but in any event, in just intonation, it won’t be 16/15ths the frequency of C.

In equal temperament, however, the notes are equally spaced. Each note is 2^(1/12) = about 1.0594 the frequency of the previous one. In equal temperament, the notes aren’t tuned to a specific key, and you can use any note in any key and get the same relative ratios between keys – at the cost of those ratios not being quite perfect. In equal temperament, C# is 2^(1/12) the frequency of C, D is 2^(2/12) the frequency of C, and C# is 2^(1/12) *below* the frequency of D, which happens to be…2^(1/12) above the frequency of C. So in this tuning, C# and Db are the same sound.

We call these kinds of notes that are the same in equal temperament but not just intonation, *enharmonically equivalent*. In equal temperament you can freely swap one for the other. In just intonation, swapping one for the other changes the quality of the interval between notes, creating a dissonant [wolf interval](https://en.wikipedia.org/wiki/Wolf_interval).

They actually have more than that. For example the note between C and D can be denoted D♭ (D flat), C♯ (C sharp) or B𝄪 (B double sharp). There is also a double flat symbol ♭♭. The white keys also have multiple names – for example C is also B♯ and D♭♭.

This is all mostly just for notational convenience. Sharp and flat signs usually last for a whole bar, or if they’re in the key signature then they last until there is a key change. To cancel them out you use a ♮ (natural) sign. But if you need to use both C and C♯ repeatedly within a bar this can get painful, so it might be more convenient to write the C♯ as D♭, or (more rarely) the C as B♯.

Also I think historically C♯ and D♭ were used to refer to slightly different frequenices. Some harpsichords even had two black keys for every one on a modern piano, tuned to those two different notes. Modern Western music overwhelmingly uses the “equal temperament” system in which there are just 12 distinct notes in each octave, so C♯ and D♭ are just two names for the same thing. But those older traditions influenced the development of musical notation somewhat.