Studies have shown that congenital amusia is a deficit in fine-grained pitch discrimination and that 4% of the population suffers from this disorder.
Ultraviolet (UV) light is light with higher frequency (lower wavelength) than visible light. UV light has frequencies ranging from 8*1014 to 3*1016 Hz (800 THz to 30 PHz) and wavelengths from 10-8 m to 3.8*10-7 m (10 nm to 380 nm). Prolonged exposure to UV light causes sunburn and can cause skin cancer.
You are right, the VLF radio stations operate down to 3Hz but much lower frequencies are possible down to 1 milliHertz Ultra-low frequency these are related to events in the magnetosphere the exact mechanism is unknown. The answer by Brian Dodson gives details for the shortest wavelengths.