A warm-up recording of Britney Spears singing her new single "Alien" from her new album "Britney Jean" was recently leaked on the web.

The warm-up version (video below) was done so that sound engineers could set their audio levels, and does not include "auto-tuning" as the official version does (video below), reports BusinessInsider.com.

William Orbit, who produced "Alien," confirmed the authenticity of the "warm-up" track on his Facebook page where he also defended Spears:

Warming up is essential if you’re a pro, as it is with a runner doing stretches, and it takes a while to do properly. I’ve heard all manner of sounds emitted during warmups. The point is that it is not supposed to be shared with millions of listeners.

A generous singer will put something down the mic to help the engineer get their systems warmed up and at the right level, maybe whilst having a cup of herb tea and checking through lyrics before the session really kicks off. It’s not expected to be a "take."

In 2013, an audio recording of Spears' isolated voice from a 2001 Las Vegas concert hit the web and sounded very rugged, notes The Huffington Post.

Back in 2011, Ke$ha slammed Spears for allegedly lip-syncing her shows.

"I don't think that's fair at all for people who are going to see the show," Ke$ha told Scotland's Daily Record. "I think if you are going to be a singer, you should sing. If you are going to be a dancer, you should dance. If you are going to do a combination of the two, you should make it very clear when you are singing and very clear when you are dancing."

(Warm-Up Version)

(Official Version)

Sources: BusinessInsider.com, Facebook, The Huffington Post, Daily Record