This Article Contains information directly from the Pikmin Games. This article is based off of an Enemy/Treasure/Area/Cave/Pikmin/Character from the Pikmin series of Games.
The Harmonic Synthesizer is a castanet. It is found on Sublevel 3 of the Glutton's Kitchen, and may be located in an alcove. Breadbugs, Anode Beetles, and other nuisances may hinder your progress in recovering this treasure.