The slightly different pitching and timing combined with the different vocal quality of each singer gives us the rich dense texture of vocal ensembles, choirs. Using the layering and processing capability of our software sequencers, we will try to emulate these changes in pitch, timing and vocal quality to make complete vocal ensemble sounds.
Why are lush vocal groups lush?
A group of people singing together creates a rich and dense texture due to the following:
- different voice qualities
- subtle timing differences
- subtle pitching differences
- singing in parts – harmony (note from each vocal is stacked one over the other, making the whole group to be singing chords)
It is probably not always easy for us to get more than 2 good singers to sing the parts. Therefore we will try to get the effects in our laptop, trying to mimic the voice, timing and pitching differences in each part of the harmony, using just one or two vocalists.
Number of singers and tracks
Two or more singers
Different people have different vocal characteristics. If you can get two different people to sing the same part, then the following techniques are likely to be even more successful, but even if you're doing this with just one voice, the results that can be achieved are often quite impressive.
Same singer sings more than one track
When the same part is sung more than once, there will always be timing and pitch differences. The differences need only be subtle, but they can give us the feeling of an ensemble, when all the different tracks with the same part are set to play simultaneously. Pan the vocals appropriately to spread the spectrum and balance the overall sound of the 'one person choir'.
Only one vocal track
If it is difficult for the singer to sing the same part more than once, then start with just one vocal track. Copy the original track to new tracks. We can use the 'duplicate track' function available in sequencers to do this.
Now we process each track with different effect parameter settings to bring subtle changes from the original in pitch, timing and timbre. More the layers with different treatments, richer the 'feeling of ensemble' can be.
What are the parameters we can tweak to get convincing results?
Voice quality differences
The timbre (quality) of a voice can change a lot with a slight shift in the formant frequency. Along with the pitch shift, many plugins offer formant frequency control also.
By using formant frequency shifts, you can change the quality of the voice in each of the track, to give the illusion of different singers in each track. Do not over do the tweaking; shift the formant frequencies just enough to make a difference.
Tuning or pitch differences
Pitch shift software
Make many number of tracks of the original vocal track. Add pitch shifting software.
Try using shifts of between +/- 3 and 12 cents, and make sure you have roughly the same number of parts singing flat as you do singing sharp so the overall pitch averages out as being in tune. If there's an audible chorus effect, you've probably gone too far.
Using pitch correction plugins
Pitch correction can sound more natural than the fixed pitch shift using pitch shift software, as mentioned above. Use pitch correction plugins like the Antares Audio Auto-Tune or Celemony Melodyne to make tracks with pitch differences from the original.
- create different tracks
- use the plugin to create natural variations in pitch. Make different corrections for the different tracks.
When the original track is played along with the different corrected tracks, it will result in a sound similar to playing different vocal tracks with natural pitch variations.
When using an auto-tuner, you can keep different response speed and correction percentage for the plugin, in each different track.
Timing differences using Delay
A positive or negative delay of 50 ms to 100 ms can help reproduce the natural time delays that occur in group singing. The delayed vocals can add up to sound dense in the final mix.
The first and last parts of the tracks with higher delay values can be made less conspicuous by fading in and fading out the beginnings and ends of the delayed parts. This will make sure that syllables in the beginning and end do not sound artificial with reference to the rest of the vocal tracks.
Use a short reverb if you don't want the chorus to sound too wet. Add reverb as send effect to each individual track, instead of applying a reverb on the whole chorus group of tracks.
To add send effect to any number of tracks, you need to open only one instance of the reverb plugin. Each track will have a section to enable and set the send effect, where you can choose to send a part of the original track to the reverb plugin.
Balance between the length and volume of the reverbs to get a neat sound which is dense enough, but not muddy. More on using your reverbs right.
Experiments with panning
Do you too see dark in the in between white squares?
The following is an example of how you can use panning to place the lead vocals, secondary vocals, and group vocals in a mix. This kind of panning tries to find pockets in the stereo field, so that no track is overlapping another or placed in the same place to become messy.
Panning is written as the side and the amount of panning. R2 means 2 points to the right of the stereo field. When you use the panning slider of your sequencer, you can see these values.
Lead vocals: 2 tracks 2R 2L
2nd lead vocals: C 10R 10 L
4 parts choir: R 90 L 90 R 70 L 70 R 50 L 50 R 30 L 30
8 panning spaces in the stereo field are allotted for the choir. There are many number of ways you can place the voices in these panned positions.
You can double the 4 voices as you wish. For example,
Mix by placing two instances of the same part in very different panning positions or assign the same to two in the similar position.
Reduce the number of positions to 4, thereby making 2 voices to overlap at the same panning position,
It maybe better to keep the bass voices near the center, so that the final mix will have the frequencies balanced well in the stereo field.
There is no end to how you can pan and arrange the vocal tracks. You could pan the whole backing group more towards one side, reduce the width of the group… Experiment with patience, listen keen, make decisions based on what is best for the situation and what appeals to you (logic and feeling).
If you have to save on the processing power of your computer, consider bouncing a set of tracks to wav, with all the effects included. Then you can start over again with a new set of untreated tracks. The effects will take up processing power and memory while the wav track of the chorus sound will only take as much resources needed for a single stereo audio track.
Patience pays. Sit with the sequencer for some time, note what works, what can be tweaked. Repeat with the other tracks and in future work. The time spent when we do it first is a good investment since it will pay off for a life time of good vocal ensemble production with the resources and equipment that we have access to.