Zooey Deschanel, Joseph Gordon-Levitt make sweet music in '500 Days of Summer'

Think it was easy casting quirky Indie rom-com "500 Days of Summer" with nontabloid treasures like Joseph Gordon-Levitt and Zooey Deschanel?

Not according to Marc Webb, who directed the film (which opens Friday) about Tom, a greeting-card writer and wannabe architect who falls for Summer, who doesn't believe in the Hallmark concept of love.

With their breakup opening the movie, the film leapfrogs through their relationship, raising provocative issues about love and friendship, and reality versus perception.

With a lot of quirky humor and an addictive soundtrack.

At a Santa Barbara Film Festival screening last weekend, Marc talked with Fest exec director Roger Durling about casting two leads who weren't on the cover of celebrity tabloids every week.

Webb met first with Joseph and they talked about who should play his love interest.

Joe actually told Marc that the actress who should play Summer was Zooey. "He had this look in his eyes," Webb recalls. "And he had that look that was Tom [his character]. But then he got depressed, 'Yeah, but no one will want to make a movie with us, we're not household names.'

Webb adds: "It's a testament to Fox Searchlight who let us make the movie with people who were just good actors, who were right for the parts even though they aren't on the cover of Us Weekly."

Watch this video and hear him explain the casting process. But crank up the volume.

Oh, and that's co-writer Scott Neustadter sitting with Webb. Neustadter wrote the script based on his real-life romantic experience. Out of pain comes art?

Video: Elizabeth Snead