A chorus doesn't get bigger only because you turn it up. It gets bigger because more voices join in, each doing a slightly different job. Backing vocals thicken the lead, add colour with harmony, and answer the lead like a second speaker in the room. You can do all of that at home with one microphone and a bit of patience.
Here is a simple order to work in, from the easiest layer to the most detailed.
Start with a double
A double is the same line as the lead, sung again. Two almost identical performances played together sound wider and more solid than one, because the small differences between them blur into a richer sound.
Sing the double right after the lead, while you still remember the phrasing. Match the timing of consonants and the length of held notes. Don't copy the lead word for word by editing it, because a copied take sounds like a thicker single voice, while a real second take sounds like two people. Pan the lead in the centre and put the double a little lower in volume, or split two doubles left and right.
Thirds, fifths and octaves
Harmony means singing different notes at the same time as the lead. The simple intervals do most of the work:
- A third above or below is the most natural harmony. Which note is a third depends on the key, so find it on a keyboard or an instrument instead of guessing.
- A fifth sounds open and hollow. It works well in rock and in folk-style choruses.
- An octave above adds brightness without changing the melody. An octave below adds weight.
Don't harmonise every note. Choose the strong words of the chorus, the hook line and the ends of phrases, and let the rest be unison or silence.
If your melody comes from a modal tradition, such as a mugham-style line with ornaments and in-between notes, western thirds can clash. Try octaves, unison doubles that follow the same ornaments, or a held drone note under the melody. Listen with your own ears, not with a rule.
Ad-libs and answers
Ad-libs are short improvised lines around the lead, such as a call back to the last word or an "ooh" that holds a note under the next line. They give a chorus movement.
Keep them out of the way of the lead's words. Place them in the gaps between lines, at the ends of phrases or in the final repeat of the chorus. A good rule is that the listener should be able to hum the lead after one listen, and the ad-libs should be a surprise on the second.
Stack, pan and blend
Four to six layers of backing vocals can turn into a soft pad behind the lead. A few mixing habits keep that pad clean:
- Put the lead in the centre. Pan doubles wide and harmonies a little less wide, so each voice has its own place.
- High-pass the backing vocals so low-frequency rumble from many takes doesn't build up and muddy the mix.
- Use a de-esser, because many "s" sounds pile up quickly when voices are stacked.
- Group the backing vocals on one bus with gentle compression, so they act like a small choir instead of ten separate singers.
- Give them a little more reverb and a slightly darker tone than the lead. That pushes them back so the lead stays in front.
- Fix timing where voices start words at different moments, and tune only what really sounds wrong. A tiny drift is part of the sound of a group.
Recording harmonies at home
Use the same microphone, the same distance and the same room for all the layers, so they blend. Sing the backing parts a little softer and breathier than the lead. A backing vocal at full power competes with the lead instead of supporting it.
Work with a reference in your headphones: the lead track plus a simple keyboard note for the harmony. Learn one harmony line at a time and record it in a few takes. Choose the vowel shapes on purpose, so everyone on the stack says "oo" or "ah" the same way. Rest your voice between sessions. Tired voices go flat.
When less is more
A chorus lifts when the verse before it was bare. If every part of the song has stacked vocals, nothing stands out. Keep the first verse close and dry, use a double in the first chorus, add harmony in the second, and bring in everything for the last one.
Sometimes a single high line over the last words is stronger than a wall of voices. Mute your backing vocals and listen to the chorus without them. If the song doesn't miss them, leave them out.