Deschanel plays piano for “So Long” and turned to the instrument when it came time to write the song. “I usually write on piano because that's the first instrument that I learned when I was a little kid,” she says. “All of my musical theory knowledge is in linear piano form.”

Her heart, however, is in the vocals. “I’m always thinking in terms of vocals, and arranging a fabric of vocals is the most exciting part. I love to sing backup parts—I always try to squeeze in as many as possible,” she says. “It’s fun; it’s my style.”

Deschanel’s songs, plus the Sherman Brothers classic and a host of original songs by Robert Lopez and wife Kristen Anderson-Lopez (“The Wonder Pets”), as well as original score from composer Henry Jackman (“The Da Vinci Code,” “Pirates of the Caribbean: Dead Man’s Chest”), will be included on the “Winnie the Pooh” soundtrack (available Spring 2011 in select international markets, and in the U.S. on July 12, 2011) from Walt Disney Records.