The London retail institution Harrods kicked off its big winter sale this week, and Florence + the Machine helped them do it in style, showing up to perform a pair of songs from the recently released 'Ceremonials'.

Frontwoman Florence Welch showed up decked out for the occasion, wearing a striking floor-length wool cape designed by Karl Lagerfeld. Check out this collision of cutting-edge pop and haute couture in the videos below!

Florence + the Machine treated the audience to live performances of 'Shake It Out' and 'What the Water Gave Me,' both from their Top 10 sophomore album, 'Ceremonials.' Already platinum in the band's native U.K., it's earned widespread critical raves and was recently named the best album of 2011 by Q Magazine.

All that success is doubly fortunate for Welch, because duds like these don't come cheap. Here's hoping for another year of healthy sales for the band!

Watch Florence + the Machine Perform 'Shake It Out'

Watch Florence + the Machine Perform 'What the Water Gave Me'