Chorus always wears out your voice.

Wanna try?

Shape your mouth to an O.

Keep it that way. Always.

Make a fist in front of your belly.

(No, don't punch it)

Sing DO in a voice like an opera singer.

(If you have no idea what an opera singer sounds like, look it up)

Hold it for 12 without taking a breath.

Keep the tall voice.

Switch to RE and hold for 10 seconds.

Keep switching.

That's how hard Chorus can be.

(Note: how hard Chorus CAN be; it could get harder)