Also called: comping
What is vocal comping?
Building one final vocal from the best parts of several takes. The editor chooses per line or per phrase and crossfades between them, which is far quicker when every take was sung with consistent phrasing.
Most comping time goes on skipping past false starts, dead air and talkback rather than on judging performances. Complete takes shrink that overhead considerably.
Crossfades placed at word boundaries between similarly phrased takes are effectively inaudible; between differently phrased ones they are not.
Recording over a specific section of an existing take without re-recording the whole track. The singer needs a couple of lines of lead-in to match the energy and phrasing of the surrounding material.
Looping a section and recording a new take on each pass, stacking them in lanes to comp from later. Every lap starts at the same point, which makes it the fastest way to gather usable options.
Stacked rows holding multiple recorded takes on one track, letting you audition and select between them. Most modern DAWs create them automatically when you record over an existing region.