Lady Gaga has surprised fans by shaving off the back of her head.

The singer is no stranger to flamboyant fashion and hairstyles, and she recently ditched her trademark blonde locks for brunette.

She posted a photo late last night (September 11) on her social networking website Little Monsters of the back of her head, with the bottom half shaved off.

It appears the move was a tribute to photographer Terry Richardson, whose mother recently passed away. She said:

"I did it for u Terry. I'm sorry about ure mommy. She has princess die, but were all princess high."

Fans commented on the photo in appreciation of Gaga's tribute, with one user posting:

"Wow people...it's about respecting someone who obviously had cancer and lost them...Seriously get over YOURSELF and understand she did it for someone ELSE. Gaga is the most selfless person...I love you for this. My Mom has cancer and I understand why you did what you did Gaga! Thank you."