The Magic Flute is found under one of the runic stones in Proxima Island. Its melodies have the power to melt frozen clear water and make flowers grow in the desert.
Twinsen uses the flute in the clear water lake to get the Flask of Clear Water. He later trades the instrument for a Space Guitar to the old man in the White Leaf Desert. With it, the old man makes flowers grow in the entire desert.
"The enchanted melodies produced by this instrument can melt frozen Clear Water and make flowers grow in the desert."