section_path: Role of conductor/Multiple conductors/Offstage instruments
section_name: Offstage instruments
paragraph_text: Offstage instruments
  
  Some orchestral works specify that an offstage trumpet should be used or that other instruments from the orchestra should be positioned off-stage or behind the stage, to create a haunted, mystical effect. To ensure that the offstage instrumentalist(s) play in time, sometimes a sub-conductor will be stationed offstage with a clear view of the principal conductor. Examples include the ending of " Neptune " from Gustav Holst 's The Planets. The principal conductor leads the large orchestra, and the sub-conductor relays the principal conductor's tempo and gestures to the offstage musician (or musicians). One of the challenges with using two conductors is that the second conductor may get out of synchronization with the main conductor, or may mis-convey (or misunderstand) the principal conductor's gestures, which can lead to the offstage instruments being out of time. In the late 20th century and early 21st century, some orchestras use a video camera pointed at the principal conductor and a closed-circuit TV set in front of the offstage performers, instead of using two conductors.