Pitch and key are not the same. Pitch is how high one sound is, measured in hertz (Hz). A key is the family of notes a song is built around, such as G major. Shift a whole song by whole semitones and its key changes; shift it by a few cents and only the pitch changes, while the key stays.
To do it to a real recording, the Online Key Changer finds the key of your song and moves it by semitones with the tempo kept, and the Pitch Shifter does free shifts in semitones and cents. Below: the four terms, the difference in one table, measured results, and which change you need.
Key vs pitch vs tone vs note: four words, four meanings
Most confusion comes from four words that are used loosely. Each one names a different thing and changes for a different reason:
| Term | What it is | Measured in | Example | It changes when… |
|---|---|---|---|---|
| Pitch | How high or low one sound is | Hz; small steps in cents (100 cents = 1 semitone) | A4 = 440 Hz | Any shift, even 1 cent |
| Note | A named pitch: letter + octave number | Note names | A4, C♯5, E♭3 | The pitch moves by 1 semitone or more |
| Key | The home note (tonic) and scale a song uses | Key names | G major, E minor | Every note moves by the same whole number of semitones (except 12) |
| Tone | (1) the colour of a sound (timbre); (2) a whole tone = 2 semitones | — / semitones | “a warm tone”; C → D | EQ, formants or the instrument; or a 2-semitone step |
So “key vs tone” and “pitch vs tone” compare different kinds of thing: a key is a set of notes, a pitch is one frequency, and tone is either sound colour or a step of 2 semitones. For the definition of pitch itself (and pitch vs frequency) see what pitch is in music; for keys, see what a song key is.
Key change vs pitch change: the difference in one table
| Key change (transposition) | Pitch change (pitch shift) | |
|---|---|---|
| What moves | The tonal centre and every note, by the same interval | The frequency of the sound, by any amount |
| Unit | Whole semitones (1 semitone = frequency × 1.0595) | Semitones and cents |
| Note relationships | Always kept: chords and melody stay the same shape | Kept, but the result may sit “between” keys |
| Works on | Sheet music, chords, MIDI, or audio | Audio (recordings, voice, video sound) |
| Tempo | Unchanged | Unchanged with a time-stretching tool; faster/slower with tape-style speed change |
| Typical size | 1–5 semitones to fit a voice | ±5–50 cents to tune; ±1–12 semitones for effects and keys |
Transpose vs pitch shift
Transposing rewrites the notes: a chord chart in C becomes a chord chart in D, with no sound processing and no loss of quality (transpose chords and notes online). Pitch shifting processes a recording so every frequency moves by the same ratio. A pitch shift of whole semitones is audio transposition; a pitch shift of 30 cents is only a tuning change.
Does changing the pitch change the key?
Yes, when every note moves by a whole number of semitones: +2 semitones takes a song in C major to D major. No, when the shift is only cents: +25 cents leaves the song in C major, just slightly sharp. A shift of exactly 12 semitones (one octave) keeps the key name, because every frequency doubles and the notes keep their letters.
Measured: what a pitch change does to the key
We shifted test files with the pitch engine behind our key changer and measured the result. The reference tone A4 = 440 Hz shows the frequency change; the key column is what a song in C major becomes.
| Shift | A4 (440 Hz) becomes | C major song becomes | Key change? |
|---|---|---|---|
| +25 cents | 446.40 Hz | C major, 25 cents sharp | No: pitch only |
| +1 semitone | 466.16 Hz | D♭ (C♯) major | Yes |
| +2 semitones | 493.88 Hz | D major | Yes |
| −3 semitones | 369.99 Hz | A major | Yes |
| +5 semitones | 587.33 Hz | F major | Yes |
| +7 semitones | 659.26 Hz | G major | Yes |
| +12 semitones | 880.00 Hz | C major, one octave higher | Same key name |
Two results from the same tests: a C major chord shifted +5 semitones came out as F major, with all four notes (174.62, 349.23, 439.99 and 523.24 Hz) moved by exactly the same ratio. An E♭ major song shifted −3 semitones was analysed afterwards as C major, still at 100 BPM and still exactly 24.000 seconds long. That is why a pitch change of whole semitones and a key change are the same thing for a recording. The test method is described at the end of this page.
What is a key change in a song?
Inside a song, a key change (in theory books: a modulation) is a moment where the music moves to a new home note. Pop songs often lift the last chorus by 1 or 2 semitones for extra energy; Michael Jackson’s “Man in the Mirror” rises by one semitone, and Beyoncé’s “Love on Top” rises four times in a row in its final choruses. This is part of the composition.
Changing the key of a song is different: the whole song, including any key changes inside it, moves by the same number of semitones. That is what singers and karaoke users do to fit their range. How to change the key of a song walks through the methods, and the semitones-to-change-key tool gives the exact count between any two keys.
What does “shift” mean in music?
“Key shift” and “pitch shift” both mean moving the sound up or down. On karaoke machines and keyboards, the ♭ and ♯ key buttons each move the music by one semitone; a display of “Key +2” means two semitones up. The karaoke pitch changer copies that layout for backing tracks.
Changes in musical pitch: sharps, flats and key signatures
In written music, a change of pitch is shown with accidentals. The ♭ (flat) sign, which looks like a small b, lowers a note by one semitone. The ♯ (sharp) raises it by one semitone, and the ♮ (natural) cancels either. A key change in a score is shown by a new key signature, usually after a double bar line: for example, two sharps (D major) replacing no sharps (C major). The music key chart lists the notes and chords of all 24 keys, and semitones explained shows how the 12 steps of the octave fit together.
When a pitch change sounds wrong
- The shift is not a whole number of semitones. A song moved by +60 cents no longer matches a piano or guitar tuned to A4 = 440 Hz. Use whole semitones if you will play or sing along.
- The speed changed too. Tape-style speed changes raise pitch and tempo together (+2 semitones = 12.2 % faster). That is a tempo problem, not a key problem: see pitch vs tempo, or change the pitch without changing the speed.
- Voices sound thin or deep. A plain shift also moves the formants (the resonances that make a voice sound like that person). Beyond about 3–4 semitones this becomes audible; the vocal pitch changer can keep the formants in place.
Which one do you need?
| You are… | You need | Do this |
|---|---|---|
| A singer: the song is too high or too low | A key change of 1–5 semitones | Find your range with the vocal range test, then read the best key for your vocal range. |
| A guitarist or pianist with a chord chart | Transposition (no audio) | Rewrite the chords, or use a capo: each fret = +1 semitone. |
| A producer tuning a sample | A pitch change in cents | Shift by cents until it matches the track, then check the key. |
| Practising with a recording | A key change with tempo kept | Follow the four steps below. |
Change the key of a recording in 4 steps
- Find the key. Open the song in the song key finder (the key changer also shows it).
- Count the semitones. From the old key to the new one, e.g. E major → D major = −2. The semitone calculator does it for any two notes.
- Shift by whole semitones. Set the number in the key changer and press Play to compare the original and new key.
- Check and download. The length and tempo should be unchanged; if a voice sounds unnatural, try one semitone less.
Frequently asked questions
Is pitch the same as key?
No. Pitch is the height of one sound in hertz; a key is the set of notes a song uses around a home note. Moving every pitch by the same whole number of semitones changes the key.
Does changing the pitch change the key?
Only when the shift is a whole number of semitones other than 12. +3 semitones turns C major into E♭ major; +20 cents keeps C major; +12 semitones keeps the key name one octave higher.
What is the difference between transposing and pitch shifting?
Transposing rewrites notes or chords into another key, with no audio processing. Pitch shifting processes a recording so every frequency moves; by whole semitones it transposes the audio.
What does key change mean?
In a song, it is a move to a new home note, often a last chorus lifted by 1–2 semitones. For singers, “changing the key” means moving the whole song up or down to fit their voice.
What is the difference between off key and off pitch?
Both are used loosely. “Off pitch” usually means single notes sung sharp or flat by some cents; “off key” means singing in a different key from the accompaniment. See common pitch problems for singers.
Is a key change the same as an octave?
No. An octave is 12 semitones, a doubling of frequency, so the key name stays the same. A key change moves the home note to a different letter, e.g. C → D (2 semitones).
More free tools for singers and musicians are on the Online Pitch Changer home page.