Name
SetMusicOnHold() — Sets the default music-on-hold class for the current
      channel
Synopsis
SetMusicOnHold(class)
Note
This application has been deprecated in favor of:
Set(CHANNEL(musicclass)=...)
Sets the default class for music on
      hold for the current channel. When music on hold is activated, this
      class will be used to select which music is played. Classes are defined
      in the configuration file musiconhold.conf.
exten=s,1,Answer()
exten=s,2,SetMusicOnHold(default)
exten=s,3,WaitMusicOnHold()