Morissette, Phair, Jason Mraz, Joss Stone, John Legend, Keith Urban, Destiny's Child's Michelle Williams and Incubus' Brandon Boyd will be featured in ads for the San Francisco retailer beginning next month, E! Online reported Wednesday.
The artists will tout their favorite Gap apparel with their favorite music playing the background.
Apple's iTunes Music Store will give free downloads to anyone who tries on a pair of Gap jeans Aug. 8 through Aug. 31.
The Gap also said Wednesday it would release a limited-edition album of the ad stars covering their favorite classic tunes.