British singer Poly Styrene, who fronted X-Ray Spex, died at the age of 53. (AP)

Her team tweeted out the sad news:

We can confirm that the beautiful Poly Styrene, who has been a true fighter, won her battle on Monday evening to go to higher places. PSTeamless than a minute ago via web Favorite Retweet ReplyPoly Styrene
Poly_Styrene

The singer told BBC last month that she would like to be remembered for something spiritual, but said, “I know I'll probably be remembered for ‘Oh Bondage, Up Yours!’”

Here's Styrene in 1977 performing her anthem for nonconformity: