What is the name of the song sung by the lady in the heineken commercials?

Clairy Browne and the Bangin’ Rackettes sing Love Letter in the 2012 Heineken commercial titled "The Switch".

Clairy Browne and her all girl harmonizing group, the Bangin’ Rackettes features a nine piece rhythm and blues big band. Her voice has been described as reminiscent of Amy Winehouse, as well as her appearance. Her main influences have been Etta James, Tina Turner, Prince to D’Angelo, Salt n’ Peppa, Sister Rosetta Tharpe, and Big Mama Thornton.

Clairy Browne and the Bangin’ Rackettes have been making an international splash with their original take on jump blues, soul, R&B, and ska. Their debut album Baby Caught The Bus was released in November 2011 and features 11 tracks of hard-edged rhythm and blues.