Lee DeWyze exchanged vows with model/actress Jonna Walsh in a vintage-inspired ceremony on Saturday afternoon. "It was really our style of wedding," DeWyze, 26, the 2010 American Idol winner tells PEOPLE exclusively. "Outdoors with chandeliers." And plenty of good music! Walsh walked down the aisle to a song DeWyze penned just for her. "It's called 'Who Would Have Known,'" says DeWyze. "It's a personal song that will be on my next album." Held in Camarillo, Calif., some 100 guests, many who flew in from DeWyze's hometown of Chicago, were in awe of the bride's Lili Bridal strapless vintage-style lace embroidered gown as she walked down the aisle. Joked Walsh, "It was mermaid shaped because I look like a ridiculous cupcake in a ball gown." After meeting in October of 2010 while shooting the video for DeWyze's "Sweet Serendipity," the couple went on their first date to a Lakers/Bulls basketball game. "When he took me home that night I called my mom and told her that I was going to marry him," says Walsh, who is taking her new husband's name. "I could feel it in my heart." "When I realized I could be 100 percent myself around her all of the time I knew I wanted to be with her for the rest of my life," says DeWyze, who popped the question on a private yacht at Disney World. The couple, wearing classic bands from Tiffany's, chose blush colored flowers, from peonies to garden roses, as accents. At the reception guests ate a Skiff's Cakes buttercream five-tier cake while sitting at tables decorated with vintage Coco Cola crates. "We also had vintage movie reels since I'm an actress," adds Walsh, "and sheets of music that were rolled up and put in jars." The newlyweds plan to honeymoon in Bali. "Lee went on his Asian tour, but I've never been there," says Walsh. "We are excited to go see some monkeys!"