Lessons · Intermediate
Transposition and Capo: Change Key the Easy Way
Move any melody or chord chart to a new key and work out capo positions without guesswork.
Transposition means moving a piece of music up or down by a fixed distance, so that it sounds higher or lower but keeps exactly the same shape. Singers transpose to fit their range, bands transpose to suit an instrument, and guitarists use a capo to play in difficult keys with easy chord shapes. Once you understand the logic, it takes seconds.
The rule: every note moves by the same interval
When you transpose, every note and every chord root moves by the same interval, and every chord keeps its quality. A major chord stays major, a minor seventh stays a minor seventh, and the melody keeps its contour. Only the starting point changes.
The quickest way to count is in semitones (half steps) on the chromatic circle:
| Semitone | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| From C | C | C#/Db | D | D#/Eb | E | F | F#/Gb | G | G#/Ab | A | A#/Bb | B |
To transpose up a major second (2 semitones), C becomes D, E becomes F#, A becomes B. To transpose down a minor third (3 semitones), C becomes A, F becomes D, G becomes E.
Transposing by interval
Pick the interval, then move each note. Here is a short melody in C major, then the same melody a major second higher, in D major:
Notice that the key signature changes too: D major has two sharps (F# and C#). When you transpose a written part, change the key signature first, then move each note by the same number of staff steps. Any accidental in the original becomes the corresponding accidental in the new key (for example, a raised note stays raised relative to the new key).
Transposing by key (Roman numerals)
For chord charts, the cleanest method is to think in scale degrees. Convert each chord into a Roman numeral in the original key, then rebuild it in the new key.
| Original (C major) | Numeral | In G major | In D major | In Bb major |
|---|---|---|---|---|
| C | I | G | D | Bb |
| Am | vi | Em | Bm | Gm |
| F | IV | C | G | Eb |
| G7 | V7 | D7 | A7 | F7 |
| Dm | ii | Am | Em | Cm |
This method has a big advantage: you also learn why the chords work together. Once you see "I vi IV V" instead of "C Am F G", you can play the progression in any key instantly.
Spelling: sharps or flats?
Use the spelling that matches the new key signature. In E major, the third of the key is G#, not Ab; in Eb major the fourth is Ab, not G#. A good rule: each letter name appears once in a major scale. If you are unsure which key to use, check the circle of fifths and the key signatures lesson.
Chords outside the key
Borrowed and chromatic chords transpose the same way. A bVII chord (Bb in C major) becomes F in G major and C in D major. Keep the numeral, move the key.
Transposing instruments
Some instruments read music written at a different pitch from the one they sound. The written note C produces another concert pitch:
| Instrument type | Written C sounds as | To write their part, transpose concert pitch |
|---|---|---|
| Bb (clarinet, trumpet, soprano sax) | Bb, a major 2nd lower | Up a major 2nd |
| Bb tenor sax | Bb, a major 9th lower | Up a major 9th |
| Eb (alto sax) | Eb, a major 6th lower | Up a major 6th |
| Eb baritone sax | Eb, an octave plus a major 6th lower | Up an octave plus a major 6th |
| F (French horn) | F, a perfect 5th lower | Up a perfect 5th |
| Guitar, bass guitar | C, one octave lower | Written one octave higher |
So if a band plays in concert F major, the Bb trumpet reads in G major and the Eb alto sax reads in D major. Guitar and bass are "octave transposing": the note names do not change, only the octave, which keeps the notes on the staff instead of on many ledger lines.
The capo
A capo clamps across all strings at a fret and acts as a movable nut. Every open-position chord shape you play above it sounds higher by as many semitones as the capo's fret number. Capo at fret 2 means everything sounds 2 semitones higher.
There are two questions you will ask:
- I know the shape and the capo fret. What chord sounds? Move the shape's name up by the capo fret number.
- I know the sounding chord. Which shape do I play? Move the sounding chord down by the capo fret number.
Example: a song in Bb with the chords Bb, Gm, Eb, F. With capo 3, move each chord down 3 semitones: G, Em, C, D. Four friendly open shapes.
Capo chart: shapes vs sounding chords
| Shape played | Capo 1 | Capo 2 | Capo 3 | Capo 4 | Capo 5 | Capo 7 |
|---|---|---|---|---|---|---|
| C | Db | D | Eb | E | F | G |
| A | Bb | B | C | C# | D | E |
| G | Ab | A | Bb | B | C | D |
| E | F | F# | G | G# | A | B |
| D | Eb | E | F | F# | G | A |
| Am | Bbm | Bm | Cm | C#m | Dm | Em |
| Em | Fm | F#m | Gm | G#m | Am | Bm |
| Dm | Ebm | Em | Fm | F#m | Gm | Am |
Read across from the shape to the capo column to find what actually sounds. Read the other way to find the shape: to sound in E, play D shapes with capo 2 or C shapes with capo 4.
Choosing the best capo position
- Pick shapes that ring. Keys with open-friendly shapes are C, G, D, A, E (and Am, Em, Dm).
- Consider the tone. A high capo (fret 7 and up) gives a bright, mandolin-like sound; it pairs well with a second guitar playing without a capo.
- Consider the singer. Transpose to fit the voice first, then find the capo position that makes the new key easy.
- Retune after clamping. A capo can pull strings slightly sharp. Check tuning with the capo on.
Practice
- Interval drill: transpose the melody C D E G E D C up a perfect 4th, then down a major 2nd. Check your answers by playing them.
- Numeral conversion: write the chords C, F, G, Am, Dm as Roman numerals in C major, then rewrite them in A major and in Eb major.
- Capo puzzle: for the sounding chords A, F#m, D, E, find the shapes for capo 2 (G, Em, C, D). Then work out what capo 5 with the shapes C, Am, F, G produces.
- Instrument part: a melody in concert C major starts on G4. Write the first note for a Bb trumpet (A4) and for an Eb alto sax (E5).
- Ear check: play a progression in the progression player, transpose it to three different keys and sing the root along.
Related lessons: Circle of fifths, Key signatures, Intervals, Diatonic harmony, Chord progressions, CAGED system.
Tools: Transposer and capo calculator, Key finder, Progression player, Circle of fifths.
Exercises and printables: Key signatures 1, Intervals 1, Circle of fifths poster, Key signatures chart, Open chords chart, Blank chord boxes.