This is a follow-up question to What's the point of keys other than C and Am?

After going through that question, I wrote down the key general facts:

  • The C major and A minor keys have the simplest key signatures.
  • Music is not about the individual notes but the relationships between them (intervals).
  • Music can be transposed to a different key. For example, vocalists music all the time to match their vocal range.
  • Keys are only identical on equal-tempered instruments
  • The chosen key is often constrained within the limits of the range of the chosen instrument.


My question is about the specific case of the piano, where I see that the points about just intonation and instrument range do not apply. Also, all the notes of the C major (C) and A minor (Am) scales are white notes on the piano.

For example, in this video of the Tetris theme tune being played on the piano in different keys, I would not have been able to guess which of them is the original or correct key. The piano seems to be an instrument where changing the key does not change much.

However, Western piano composers, old and contemporary, have not composed all their music in C or Am, or at least started there if they intend to change the key later (modulation). For example, Moonlight Sonata is in C-sharp minor.

If music sounds similar in each key, why would a piano composer choose a key over another? Why not just start composing a song in the simplest key for piano?

  • Comments are not for extended discussion; this conversation has been moved to chat.
    – Dom
    Commented Sep 20, 2022 at 16:35
  • Please keep discussions about the questions in the chat. Any further comments will be deleted since they can't be moved into chat.
    – Dom
    Commented Sep 20, 2022 at 18:44
  • Your idea seems to be because you can transpose and relative harmonic relationships are important, that "music is not about the individual notes" and the various keys are redundant. Wrong. First, range matters. Higher or lower ranges move into different keys. Second, and more fundamentally, the relative relationship and contrast of multiple keys is more of the most important aspects of harmony and composition. Commented Sep 21, 2022 at 15:16
  • A simple analogy can be had from art. You can paint a monochromatic picture and still recognize the subject, therefore multiple colors are redundant. Both ideas, one key signature and one color painting, are silly for obvious reasons. Commented Sep 21, 2022 at 15:19

3 Answers 3


C and Am are NOT always the easiest keys - and I'm considering piano here. Just because they both (presumably) use the 'white keys' doesn't make the pieces easier to play. There are many, many pieces that have been written in different keys, and I'd challenge anyone to play them as well in key C/Am.

Mainly due to fingering. It may appear, mainly to beginners, that any piece is easier to execute in key C/Am, but once you've tried using the black keys as well, it becomes obvious that there will be better keys than those!

I really don't think it's much to do with what each key sounds like individually - with 12tet being the normal piano tuning, that won't make any difference to most, if not all listeners/players.

All that apart - I can't think why anyone would go to a concert and listen to piece after piece in the same key! I certainly get fed up after about 3 in the same key when I'm playing - so use my key change to play in a different key if the next number is another. It does relieve the boredom, and we do tend to think differently in different keys, although I can't reason why.

  • Any input on what the easiest keys actually are? Or examples of pieces written in different keys which would be more difficult to play in C or Am?
    – hb20007
    Commented Sep 20, 2022 at 15:36
  • 4
    @hb20007 - it will depend wholly on what piece is in question. That's like asking 'which are the easiest tools to use...' or 'which are the best paintbrushes to use...'
    – Tim
    Commented Sep 20, 2022 at 15:39
  • Wow @Tim. Another question answered by you that is then closed by you. Is reputation removed after an question is closed? Commented Sep 21, 2022 at 15:13
  • @MichaelCurtis - I was waiting for this comment! The answer seemed too obvious to miss. Then, on reflection, I found a dupe. Is it now down to me to check out everything first? 'Cos I probably won't... Don't think rep is removed - don't mind if it is.
    – Tim
    Commented Sep 21, 2022 at 16:21

There are many reasons why composers would prefer to write for piano on keys other than C or a. For instance:

  • Absolute pitch of notes and phrases. The same theme played in C major and in G major sounds rather different simply because all notes in it are a fifth higher. The impact on a sensitive musical listener can be quite significant.

  • Simple variety. A dozen piano sonatas all in C major would quickly become hard to tell apart even for the author.

  • Limitations of the instrument. The keyboard isn't infinite, and romantic composers permanently pushed the boundaries of the piano (you can tell exactly what the highest note on Chopin's instrument used to be simply because all of his pieces go only so high). Having or not having a specific note available at the top or bottom of the range can make or break the conception of an entire movement.

  • Playability and readability. There is a reason why many sonatinas for beginners, and many first symphonies even of the greatest composers, are written in C. Conversely, music in C has an undertone of being beginner's music; when Paul Dukas chooses E flat minor for his piano sonata, you know that he means business!

  • 1
    You don't have to have perfect pitch do perceive a motif played in G vs the same motif played in C differently. The timbre of notes always changes subtly across the range of an instrument. For instance, the difference in character between the lowest and highest C on a concert flute is extreme. With a difference of just 7 semitones the effect is of course smaller, but it is there. Commented Sep 20, 2022 at 15:13
  • 2
    The timbre of notes on some , maybe most instruments, will change, but on piano, I doubt there's any difference in timbre between playing a piece in, say, F#. And OP is asking specifically about piano, not guitar or flute. The point about a sensitive listener' may be relevant, but for the vast majority, no-one would notice.
    – Tim
    Commented Sep 20, 2022 at 15:37
  • 1
    @Tim I passionately disagree. The greater part of the genius of music is that hearers are reliably affected differently by changes in parameters that they claim not to perceive, and couldn't consciously distinguish. Commented Sep 20, 2022 at 16:11
  • 2
    @KilianFoth - This is tantamount to "D minor is the saddest key" which is a meme that will not go away, long after it was suitably ridiculed in Spinal Tap The dependancy of the claim really only works before the invention of equal temperament.
    – Tetsujin
    Commented Sep 20, 2022 at 17:07
  • 1
    @Tetsujin No, it isn't. I am nowhere referring to the character of keys that used to be caused by different micropatterns between the semitones. The point is simply that the same starting chord in C will sound differently when when shifted up because of the shift. For instance, there is a limit to how low a specific triad sounds reasonably transparent when you transpose it down; moving tings up and down will change the degree to which this applies. Claiming that this makes no difference to listeners is simply wrong. Commented Sep 21, 2022 at 6:50

Piano music sounds best when much of the music hangs around middle C; that is, the instrument usually sounds good when at least the accompaniment parts are in the middle range. Too much to the bass side can make the music sound "muddy" and too much to the treble side can sound "tinny" though there is music that takes advantage of these ranges. Even though the piano may be tuned in equal temperament, the absolute pitches matter. Notes on a piano have different numbers of strings so the quality of the same named note in different octaves does sound different.

If one takes a piece and transposes it up (or down), the melody and bass just get moved but the accompaniment (the notes between the melody and bass) may change. For example, if a piece is raised up around half an octave (from C to F or G, for example), A C-chord that was written as C-E-G may be changed to a G chord as B-D-G (rather than G-B-D) to keep the total range around the middle of the keyboard. The overall texture becomes different; not necessarily better or worse, but different. Composers usually have a particular sound in mind.

If a piano were tuned in a non-equal temperament; transposing a melody may change the character entirely. The main points of the music will be the same (a perfect cadence is still a perfect cadence; a G chord followed by a C chord still sounds like a cadence, but the "tone color" of the piece changes.

  • 2
    Sorry, but none of this rings true. A piece could be in just about any key, and still be played on 3 strings, that pianos have in the several octaves in mid-range. There would also be no need to change inversions of chords for the same reason. -1.
    – Tim
    Commented Sep 20, 2022 at 15:45

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