DAVE: I can play you a song we demo’d a couple weeks ago using a drum machine.
A demo (short for demonstration) is a song or group of songs recorded by a band that can be handed on to record labels, producers, or other artists. Bands also record demos for their own use and reference.
A drum machine [pictured] is an electronic musical instrument that creates percussion sounds, drum beats, and patterns. Drum machines may imitate drum kits or other percussion instruments, or produce unique sounds, such as synthesised electronic tones. A drum machine often has pre-programmed beats and patterns for popular genres and styles, such as pop music, rock music, and dance music. They have been commonly in use since 1980.
Dave’s band obviously used a drum machine on their demo because they didn’t have a drummer – now they do.
The Annotated Gilmore Girls 