Narrations and Music
When one chooses to "preview" a trip, a narration introduces the trip as selected pictures from that trip are displayed.
And in the tour section, a naration will describe the wilderness or park in the Sierra as selected pictures from that area are shown.
There are fourteen music selections available that can play as background to a walk on the map, or tours or trips. You can disable any (or all) of these that you would prefer not to hear.
Sample music selection (viewer requires MIDI player)