Picture: William Orbit press image 2009
The Toxic superstar teamed up with Orbit, most famous for his work on Madonna's Ray of Light and Music albums, on the song for her 2013 album Britney Jean.
The track came back to haunt Spears this week (beg07Jul14) when a raw clip of the song appeared online, prompting fans to take to social media to mock the singer's out-of-tune vocals.
Orbit has now spoken out in her defence, insisting the singer was warming up to help studio engineers prepare their equipment.
In a post on Facebook.com, he writes, "Dearest Music Lovers, I have heard that Britney vocal link that everybody's been discussing. It has been impossible not to as there have been many comments directing my attention to it... I'd like to affirm that Any singer when first at the mic at the start of a long session can make a multitude of vocalisations in order to get warmed up.
"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 warm-ups. 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'."
The producer went on to slam the culprit behind the leak, adding, "Whomever put this on the Internet must have done so in a spirit of unkindness, but it can in no way detract from the fact that Britney is and always will be beyond stellar! She is magnificent! And that's that."