Evil Trees is a warning played when you near the animated trees protecting a certain area of the map. If Rosella gets too close, the tress will grab her! William Goldstein composed the song in a lower octave to add mood.
King's Quest IV: The Perils of Rosella (DOS)
Five different types of output were designed for the DOS release, each output corresponds to a different group of devices, the Roland, Yamaha, OPL2, 3 Voice, and PC Speaker.
The file is sound.064 in the resource files.
It is unknown if the Amiga, Apple II, Apple II GS, or Atari ST ports have this song.