Is any technology used to enhance the sound of the backup vocals in Twisted Measure's version of Sia's "Chandelier"? Are any particular effects or filters being used over the backup vocals? One of my friends suggested that auto tune was used, but I don't necessarily think that would be required to produce the sound.
The choir vocals are very obviously auto-tuned. Almost all pop songs nowadays use this. The effect has become so ubiquitous that that's the only sound a lot of people know. They're also using some reverb,