Rhapsody in Blue by George Gershwin
Almost anyone can recognize Gershwin's Rhapsody in Blue. Like, Orff's O Fortuna, Rhapsody in Blue is featured in many movies and television shows. Some consider it strictly jazz while others say it's classical, when in all actuality, it's a perfect combination of both. Here's an interesting fact, when Gershwin was commissioned to write the piece, he wrote it so speedily he didn't have time to compose the part for piano. At its first performance, Gershwin improvised the piano part. Later, it was finally composed.
Hear Gershwin's Rhapsody in Blue in the movies Fantasia 2000 and Manhattan.