OVERTURE noun 1. A piece of orchestral music played at the beginning of an opera or oratorio, often containing the main themes of the work or quotations from the work that is to come. 2. Approaches made with the aim of opening negotiations or establishing a relationship. 3. The first part of an event. The very beginning of something. The gateway story to the ground-breaking and New York Times best-selling Sandman series by multi award-winning author Neil Gaiman is collected here in an Absolute over-sized edition. Collects The Sandman: Overture #1-6.