The tonic is the first degree of a scale and the home note of a key: in C major the tonic is C, and the tonic chord, C major, is the chord that melodies and progressions return to. The tonic is the most stable note in the scale, and all other notes are heard in relation to it.
What is the tonic in music?
The tonic is the first degree of a scale and the home note of a key. In C major the tonic is C, in G major the tonic is G, and in A minor the tonic is A. The tonic is the note that the scale is named after, the note that melodies return to, and the note that the tonic chord is built on. It is the most stable note in the scale, and all other notes are heard in relation to it: the dominant pulls toward the tonic, the leading note leans toward the tonic, and the subdominant sits a 5th below the tonic. The tonic matters because it is the centre of gravity of a key. A piece of music in C major is not just a collection of notes from the C major scale: it is a journey that starts at the tonic, moves away from it, and returns to it, and the return is what gives the music its sense of completion. The final chord of a piece is almost always the tonic chord, because ending anywhere else sounds unfinished, like a sentence without a full stop. The C major scale starts and ends on its tonic, C, and the key of C major is built around it.
How the tonic works
The tonic is the 1st degree of the scale, and the tonic chord is the I chord in a major key and the i chord in a minor key. In C major the tonic chord is C major, C, E and G, and it is the most stable chord in the key. In A minor the tonic chord is A minor, A, C and E, and it is the most stable chord in that key. The other chords of the key are heard in relation to the tonic chord: the dominant chord, V, pulls toward the tonic, the subdominant chord, IV, sits a 5th below the tonic, and the vi chord, the relative minor, shares the tonic's notes but has a different home. The tonic is also the note that the key signature is organised around. The key signature of C major has no sharps or flats because the C major scale has no sharps or flats, and the key signature of G major has one sharp, F#, because the G major scale has one sharp. The tonic is the note that the scale starts on, the note that the key is named after, and the note that the music returns to, which is why it is called the tonic, from the Greek word for tone, the note that sets the tone of the whole key. The scale degree calculator finds the tonic of any scale, and the key finder finds the tonic of a set of chords.
Worked example — the tonic in G major. The G major scale is G, A, B, C, D, E, F#, G, and the tonic is G, the first and last note of the scale. The tonic chord is G major, G, B and D, and it is the chord that the I–V–vi–IV progression in G major starts and ends on, in its full form, G, D, Em, C, G. Play the progression and listen for the music leaving the tonic on the V chord, D, wandering to the vi and IV chords, Em and C, and then returning home to G. The G major guitar chord is the tonic chord, and the key of G major is built around it.
How to practise hearing the tonic
Practise hearing the tonic by listening for the note that the music returns to, and by playing progressions that start and end on it.
- Play the C major scale ascending and descending, and notice that the scale starts and ends on its tonic, C.
- Play the I–V–vi–IV progression in C major and listen for the music returning to the tonic chord, C, at the end.
- Listen to a song you know and try to hum the tonic note, the note that the melody keeps returning to, before you check it against the instrument.
- Play a random chord from the key of G major and then play the tonic chord, G, and listen for the feeling of arrival.
- Use the key finder to find the tonic of a set of chords, and check your answer by playing the tonic chord.
Common mistakes
- Confusing the tonic with the first note of the melody — A melody can start on any note of the scale, not just the tonic, and the first note is often the 3rd or the 5th. The tonic is the note that the music returns to, not necessarily the note that it starts on.
- Thinking the tonic is always the lowest note — The tonic is the home note of the key, but it can appear in any octave and in any position in a chord. A tonic chord in first inversion has the 3rd in the bass, but its tonic is still the root, not the bass note.
- Forgetting that the tonic chord can be minor — In a minor key the tonic chord is minor, not major, and it is written with a lowercase i. A minor's tonic chord is Am, not A major, and the two sound completely different.
Quick reference
This table lists the tonic note and the tonic chord of six keys, so you can see that the tonic is always the first degree of the scale and the root of the tonic chord. In a major key the tonic chord is major, and in a minor key it is minor, but the tonic note is the home in both cases.
| Key | Tonic note | Tonic chord |
|---|---|---|
| C major | C | C major (C – E – G) |
| G major | G | G major (G – B – D) |
| D major | D | D major (D – F# – A) |
| F major | F | F major (F – A – C) |
| A minor | A | A minor (A – C – E) |
| E minor | E | E minor (E – G – B) |
Work through the table by playing each tonic chord on your instrument, and listening for the feeling of home that each one gives. When you can hear the tonic as the centre of gravity of a key, try the exercise with a song you know: hum the tonic note, and check it against the instrument.
Frequently asked questions
What is the tonic in music?
The tonic is the first degree of a scale and the home note of a key: in C major the tonic is C, and the tonic chord, C major, is the chord that melodies and progressions return to. The tonic is the most stable note in the scale.
How do I find the tonic of a song?
Listen for the note that the melody keeps returning to, and look at the final chord, which is usually the tonic chord. If the song ends on C major, the tonic is C, and the key is C major or A minor, depending on the final chord.
What is the difference between the tonic and the root?
The tonic is the home note of a key, while the root is the home note of a chord. In C major the tonic is C and the root of the C major chord is also C, but the root of the G major chord in the same key is G, while the tonic of the key is still C.
Can a piece have more than one tonic?
A piece can modulate, which means it changes tonic, but at any given moment it has one tonic. A song that modulates from C major to G major has two tonics in total, C and then G, but only one at a time.
Why is the tonic so important?
Because it is the centre of gravity of a key: all other notes and chords are heard in relation to it, and the return to the tonic is what gives music its sense of completion. Without a tonic, music sounds lost, with no home to return to.