Britney Spears - Telephone demo

Apparently, the song was originally written for her. From Wikipedia:

Gaga originally wrote "Telephone", with Rodney Jerkins, for Britney Spears. However, Spears' label rejected it and Gaga recorded the song as a collaboration with Beyoncé Knowles for The Fame Monster. Gaga said, "I wrote it for her a long time ago and she just didn't use it for her album. It's fine because I love the song and I get to perform it now." Additionally, the guest vocalist was originally going to be Spears, but for an unknown reason, Gaga made Knowles the featured vocalist instead.

Even though it's only a demo, this version still kinda kicks Lady Gaga's version's ass.

via