Sara Bareilles, Liz Phair, OK Go and Tommy Torres will join five other artists as the faces of Banana Republic's spring and summer ad campaigns.

The national campaigns will feature print advertising, window displays and billboards identifying the artists wearing the company's clothes. Banana Republic customers will receive an iTunes gift card with purchase from Feb. 17-26, redeemable for a free compilation of songs by the participating artists.

Acoustic soul singer Ayo, Dashboard Confessional, jazz artist Esperanza Spaulding, saxophonist David Sanchez and classical violinist David Garrett are also part of the initiative.

During the campaign's second phase, expected to begin in May, another set of digital tracks will be released by the same nine artists -- this time original songs they composed especially for the retailer's "City Stories" theme. Those will be housed on the campaign's microsite, where visitors can also access free downloads, videos and interviews with the artists and link to iTunes directly.

In addition to the advertising and digital content, artists will receive in-store play and have recorded voice-overs to introduce their songs. The in-store playlists also include songs by other acts that the artists recommend. Garrett, Sanchez and Puerto Rican singer/songwriter Torres will perform invitation-only acoustic sets at Banana Republic stores in New York, San Francisco and Los Angeles on Feb. 26.

"City Stories" was executed by New York agency AR, with artist casting support by Starworks and music aggregation and marketing by San Francisco-based Rock River Music.

Banana Republic's chief marketing officer Peter DeLuca tells Billboard that the campaign began by targeting "the modern soul": shoppers between the ages of 25 and 49 who "aspire to a city lifestyle," says DeLuca. "We're really trying to establish the brand's vision of the city as an anchor point. Music is a key piece of the puzzle."

So is the online aspect, says DeLuca. "We wanted to do something that broke out from the way we were traditionally marketing in the past," he says. "We are definitely leveraging online as a means to deliver a large portion of the campaign and give a visual and audio component to the brand."

Artists were chosen for their diversity of genres, their single or album release schedules, and if they'd feel right in Banana Republic clothes. The campaign is kicking off just as Torres is releasing a deluxe edition of his Warner Music Latina album, "Tarde O Temprano". His new single, "Imparable", is featured in the Banana Republic compilation.

Slightly more information from Billboard.biz:

"Besides the clothes, they're focusing on showcasing talent, and it's great exposure for my music," says Torres. "If someone Googles me or ends up on my MySpace or Web page, that can only be good… There are Latin people that shop at Banana Republic, but also non-Hispanic, so I’m sure it'll be all new to them."

Torres said he was selected after the casting company, Starworks, contacted his management through his Web site. He says he was paid a flat fee for his name and likeness, and that production costs were also covered for his "City Stories" -themed original song—which his label will end up owning. A negotiated publishing fee and some performance royalties from online streaming and in-store play will also come from use of his music. "It's not a crazy amount of money, but it's respectable," says Torres.

Rock River Music creative director David Hargis, whose company commissioned the artists' original songs, adds, "The labels and publishers recognize that this was a significant opportunity, because Banana Republic has such marketing muscle with these print ads and billboards… getting a label budget to pay for a giant billboard in big cities, that's difficult to do."

Video has surfaced of Liz at that Smith College discussion panel over at Facebook.