Intonation is how well your notes sit in tune: not just the right note, but the right part of it. The quickest way to train it is a drone: one steady note held under you while you sing. A drone never drifts and never hurries, so it shows you every small slip, and it lets you hear in tune instead of guessing at it.
Why a drone works
When two notes are almost the same pitch, they wobble against each other. That wobble is called beating, and its speed is the difference between their frequencies. A note 10 cents away from an A at 440 Hz beats about two and a half times a second; as you get closer, the wobble slows down, and when you're exactly on the note, it stops. You don't need to know any of that to use it: you listen for the wobble and move until it goes still.
A tuner tells you the same thing with a needle, but you end up watching instead of listening. A drone trains your ear, which is the thing you'll have in rehearsal.
Set it up
- Pick the key note. The drone plays the home note of the key you're working in, the first note of its scale. If you're practising a song, use the song's key.
- Put it where you can sing it. Choose a key note in the lower middle of your voice, so its note is easy to hold and the scale up to the octave above stays comfortable. The drone can sound that note or the one an octave below.
- Keep it soft. Quieter than your voice. If you have to push to hear yourself over it, turn it down.
- Use headphones if you can. You'll hear the beating more clearly, and your phone's microphone won't pick up the drone if you're also recording. Keep them quiet enough that you still hear your own voice, so you don't push.
- Warm up first. A minute of humming or gentle slides up and down before you start holding notes.
The free drone tool plays any key, with or without its fifth, and can tune its chords pure.
Exercise 1: one long note
Sing the drone's own note on an easy "oo" or "ah", softly, and hold it for a slow count of six. Listen for the wobble. If you hear it, move your note very slightly up or down. If the wobble gets faster, you went the wrong way: go the other way until it slows and stops. Then stop before you run out of air: the end of a breath is where notes sag.
Do this three or four times. It's the whole skill in miniature: land, listen, settle.
Exercise 2: the fifth
Now sing the fifth note of the scale, counting the drone's note as one (sol, if the drone is do). The fifth blends with the drone so smoothly that when you're on it, the two seem to merge into one fuller sound. When you're a little off, you'll hear it rub. With a fifth or a third, the wobble comes from the notes' overtones rather than the notes themselves, so it's fainter: listen closely. Hold it, listen and settle, just as before.
A pure fifth sits a tiny bit wider than a piano's, about 2 cents, too small to aim for on purpose. Your ear finds it by itself when you listen for the stillness.
Exercise 3: a slow scale
Sing up the scale from the drone's note and back down, slowly, stopping on every note. Some notes will settle easily against the drone (the octave, the fifth, the third). Others will feel restless (the second and the seventh want to move on). That restlessness is the scale's own pull, and hearing it is part of singing in tune: it tells you where a note is heading.
Take your time on the way down. Many singers tune each note a little too low when they descend, so the scale sinks; make each step down the same size as that step was on the way up.
Exercise 4: thirds that ring
The third above the drone (mi, if the drone is do) is the note that makes a chord sound major. Sung against a drone, a third rings best a little lower than a piano plays it: a pure major third is about 14 cents below the piano's. That's about a seventh of the way to the next note down: small, but you can hear it.
Sing the third and hold it. Bring it down very slightly until the rough edge disappears and the two notes lock. Barbershop singers tune their chords this way, and when every voice does, a chord rings so clearly that some people hear an extra, higher note in it. The free just intonation tuner shows how far your third sits from pure.
Then try the minor third (a little higher than the piano's, about 16 cents) and the sixth (a little lower than the piano's, also about 16 cents).
Exercise 5: a tune over the drone
Sing a simple tune you know over the drone on its key note: Simple Gifts, Amazing Grace, or a folk tune. The drone keeps you honest through the whole line: every long note gets a moment to settle, and if the tune drifts flat, the drone shows you exactly where. Some notes rub against the drone on purpose, where the tune moves away from the home chord; judge your tuning on the long notes on do, mi and sol.
Singing over a drone is old and widespread: the tanpura under Indian classical singing, the ison under Byzantine chant, the hurdy-gurdy and bagpipe in European folk music. Many old modal tunes sit beautifully over one.
How long, and how often
Little and often beats long and rare. Five to ten minutes a day is plenty. Stop while your voice still feels easy: the aim is to train your ear, and a tired voice tunes worse, not better. If your throat feels tight, scratchy or hoarse, stop for the day.
When it doesn't settle
- You can't hear the wobble. Turn the drone down, sing more quietly, and use headphones. Try another vowel: "oo" works well for the drone's own note; for the fifth and the third, an open "ah" gives the wobble more overtones to show up in.
- Every note sags at the end. That's usually breath, not ear: stop the note while it's still steady, before the air runs out. Breath and stamina's lesson "End on purpose" works on exactly this.
- You slide up into each note. Hear the note in your head first, then start it right there. Perfect your pitch's first lesson, Bullseye, trains landing without the slide.
- It sounds right but the tuner disagrees. A tuner measures the piano's tuning. Against a drone your ear wants pure intervals, and a pure third really is lower than the piano's. Trust the stillness.
Practise it in Stackapella
- The beginner course's second unit, Steady notes, has a lesson called Against a drone: hold your note over a drone, and the app scores it against the drone.
- Perfect your pitch takes it further: landing on a note cleanly, holding it, and tuning to a drone until it rings. It's free, like every course.
- Barbershop and tags starts with A chord that rings: you hold the third while three other voices sound around you, tuned pure. It's free too.
- In the app's Sing, any song can play a drone under you, its key note or its chord, while you learn your part: it's in Sing's settings, under Practice, free for everyone.