Scrum is a project development framework frequently used in software development and specifically game development. It is an agile development method with a strong focus on visibility, accountability, team dynamics, quick pivots and finishing demoable product. It has been an essential tool at BioWare San Francisco for managing the breakneck pace of live game development, and has been transformative in my own time serving as a game producer.
There are numerous resources throughout the web that can educate you on the Scrum process. I found this brief video from Jeff Sutherland that explains the foundation of and basic tenants of Scrum. This posting explains the various Scrum concepts I reference heavily in the posts related to the Scrumification of Music, as I interpret them.