This database indexes fakebooks in the San Francisco Public Library's reference collection. Fakebooks are printed music collections that contain simplified versions of songs and instrumental music. Usually they contain only melody, lyrics, and a chord progression. The lyrics may be incomplete, and musical introductions and interludes are frequently omitted. Fakebook arrangements are also called lead sheets and are popular among jazz and lounge musicians. Lead sheets provide the minimal music information needed for musicians to create their own arrangement on the spot. As a result a single fakebook can contain hundreds of musical works.