Kate Nash majorly switches up her sound on "Under-Estimate The Girl."

No one ever accused British singer-songwriter Kate Nash of being too sweet. Her funny and sharp lyrics have always been able to put people in their place. (Remind us to NEVER cross her). But apparently after a late night rehearsal, Kate needed to blow off some steam, and the result is probably the most hardcore thing we've ever heard homegirl do.

Watch Kate Nash "Under-Estimate The Girl" after the jump.

With a lilting and moody guitar and bass backing her up, we don't hear her beautiful yet sardonic singing voice, but a gruff growl that's way new to us. Where is this coming from? Who made her mad? We wouldn't wanna be them. Getting some advice from her new guitarist, she said on her site "Linda (my shiny new guitarist) told me to RELEASE THE BEAST! so I did." And she so does. It's almost like a completely different person! Now we don't know if this is just a one-off song or if she plans to record more music like this (hopefully we'll get a little of both), but it def seemed therapeutic. AND it will be no cost to us. For a limited time, the song is a free download on her website. We'll take that, thank you.

+Watch Kate Nash "Under-Estimate The Girl".

Photo credit: UMG