It's easy to tell who can sing in the group

(They're the ones with proper mikes: TaeTiSeo + Sica)

These girls will sing unsupported depending on the intensity of the performance (e.g. if there's a lot of dancing involved or if they have to do several acts in a row). Everyone else performs either partially or fully supported.

For anyone who's never worked with audio equipment before, here are some things about microphones: if it's not right in a performer's face, it's not being used properly; if the top isn't directed at the mouth, it's not being used properly.

If you hear the premix mike tracks from live performances, Taeyeon is fucking loud; she's got real pipes.

(Well okay, all of them can sing "above average", but most of them aren't there on account of their singing abilities)

Their new album dropped on New Year's, performances at that time were fully synced, presumably to get them familiar with the live choreo first.

They haven't gotten all the live vocals nailed for I've Got a Boy yet. Probably because the dance for it is more physically intensive than normal.

(The choreo is from Nappytabs, if anyone cares)