Breakaway music is a modern U.S. Naval tradition used to motivate sailors upon the conclusion of underway replenishment UNREP, although using breakaway music is at the discretion of the Captain, and not all commands use it. When the two ships involved in the UNREP conclude their transfer of fuels and stores and commence their breakaway, a song (usually selected by the Captain, but sometimes picked by the OOD or Navigation Officer) is played over the 1MC. Breakaway music may sometimes be related to the name of the ship, such as the "Theme from Star Trek" (USS Enterprise) or "Kansas City Lights" (USS Kansas City).