Second voice
A second voice is a melody that goes along with the main one at a different pitch, usually a third or a sixth above or below, the way vocal duos and choirs sing harmony. Choose a public-domain melody, type or sing your own, and this page writes the second voice on the staff, keyboard, guitars and wind instruments, plays both together and helps you practise singing or playing your part.
1. The melody
Melody only: no lyrics.
Type C D E F G A B (or do re mi fa sol la si), # and b for sharp and flat, :2 for 2 beats, :1/2 for half a beat, p for a rest. Without a number, each note goes to the octave closest to the previous one; ' raises it an octave and , lowers it.
Length
Turn it on, wait for a one-bar count-in and sing (or play) the melody in time with the click. Nothing is recorded: the device only writes down the notes.
2. The second voice
Style
Transpose · Range of whoever sings the 1st voice · Chords
E.g. C | G7 | C F | G C. In the choir style, the 2nd voice prefers chord notes on the strong beats.
3. See
Choose, type or sing a melody to start.
The numbers between the staves are the intervals (3 = third, 6 = sixth, 8 = octave). Tap a note in the 1st voice to fix it.
Tab for both guitars and the positions on the fretboard: filled = 1st voice, ring = 2nd voice. The guitar sounds an octave lower than written.
Each staff is written the way the player reads it (already transposed for the instrument). In red: outside the comfortable range.
4. Listen
5. Practise
The app plays one voice and you sing or play the other. Each note lights up green (right), yellow (close) or red. Nothing of your voice is recorded: only the score stays on the device.
I take
Listening
Without headphones, the other voice plays quietly and the microphone ignores anything that matches it. Sing much louder than the phone (or use headphones: it works much better).
Strictness
Result
0 out of 100
What is a second voice?
A second voice is a melody that moves together with the main one, sung or played at the same time at a different pitch. It follows the rhythm and shape of the first voice and forms intervals with it that sound good together: in popular music, almost always thirds and sixths. It is what makes a duo sound like a duo, a choir sound full and two guitars sound like one, only wider.
The first voice is the melody everyone knows. The second can sit above it, as in Brazilian country duos, or below it, as is common in choirs and churches. Whoever sings the second voice has to hear the other one without being pulled along by it, which is why practising with the other voice playing helps so much.
Thirds and sixths
The third is the most common interval: the note of the key two steps above (or below) the melody. In C major, the third above C is E, above D it is F and above G it is B. Because it is counted within the key, the third comes out major or minor depending on the note, and both voices always stay in the same scale.
The sixth is an inverted third: the third below, moved up an octave, becomes the sixth above, and vice versa. Both sound sweet and blend with the melody. The fifth sounds more open and more ancient, and it is the one that gives away tuning slips the most. Where the fifth in the key would be diminished (B and F, in C major), the page puts a third in its place.
Country duo and choir
In a Brazilian country duo (sertanejo), the second voice usually sings thirds above the melody. When the third would go too high for the voice, it moves below and becomes a sixth, then comes back when it can. The page chooses where to make that switch by looking at the whole song: it switches as few times as possible and, preferably, after a rest or a long note, as a singer would.
In a two-part choir, the second voice needs a life of its own. The page chooses the whole line at once: it prefers thirds and sixths, avoids parallel fifths and octaves, favours contrary motion, takes the leading note to the tonic and ends on the tonic. If you enter the chords, the second voice prefers chord notes on the strong beats.
How to use it
Choose the melody: one from the library, typed (C D E or do re mi, with the keyboard or the guitar fretboard) or sung into the microphone in time with the click. Check it on the staff and tap a note to fix it.
Choose the style and the range: third, sixth or fifth, country duo or choir, and the range of whoever sings the second voice. If you have taken the vocal range test, the page uses your voice; “Find the key for both voices” transposes the song so both parts fit.
See, hear and practise: the staff shows both voices and the intervals between them, and the keyboard, guitars and winds show the same for each instrument. Play both voices, mute one to hear the other and, in practice mode, sing your part while the app plays the other one. Headphones are recommended: without them, the microphone hears both voices mixed together.
Why only public-domain melodies, and no lyrics
The library only has public-domain melodies: folk songs collected more than a century ago, hymns and classical pieces. Each one says who wrote it and when, why it is in the public domain and where the notation came from. When the status is in doubt, the melody stays out.
Lyrics are left out, even for old songs: only the melody and the title. The lyrics (or their translation) may have an author of their own even when the melody is old, and the second voice does not need them. To work on a song that is not in the library, type or sing the melody: nothing leaves your device.
Also in singing: vocal range test · best key for your voice · voice tuner · everything about singing
A ready-made second voice in every key
The scale of every key with the second voice worked out note by note: in thirds, in sixths, the way Brazilian country duos sing it and for two guitars. Each page opens the tool in that key.
To understand why each note works, read the guide to singing a second voice .
Country duo
Frequently asked questions
How do you sing a second voice?
The simplest way is to sing the third: for each note of the melody, the note of the key two steps above (or two below). When the third gets too high or too low, move to the sixth on the other side. The page does this for any melody and shows the result on the staff and the keyboard, so you can hear it before you sing.
What is the difference between a third and a sixth?
A sixth is an inverted third: the third below, an octave higher, becomes the sixth above. Both use the same notes and sound sweet with the melody; the third stays closer to the first voice, and the sixth further away.
How do Brazilian country duos sing harmony?
Usually in thirds above the melody. When the third would go beyond the singer’s range, the voice drops to the sixth and then comes back. The page’s “Country duo” style follows that approach and switches sides as little as possible.
Can I practise the second voice on my own?
Yes. In practice mode, the app plays the first voice and you sing (or play) the second. Each note lights up green, yellow or red, and at the end you get a score from 0 to 100. It works much better with headphones, because the microphone hears only you.
Does it work for instruments?
Yes. The Guitars view shows the tab and the fretboard for two guitars (or one guitar in double stops), and the Winds view writes each voice already transposed for flute, clarinet, saxophones, trumpet, horn or trombone, marking the notes outside the comfortable range.
Is my voice recorded?
No. The microphone only reports the pitch at each moment, which becomes a note or a score right away, inside the browser. Nothing is recorded or sent; only the best score for each song stays on the device.