A band called 'Between Music' are set to play their first underwater gig next week.
The Danish ensemble is the first of its kind in the world, and will play Aquasonic at Rotterdam next Friday (May 27).
The group will play instruments and sing inside water tanks - using techniques that have taken 10 years to develop, according to Oddity Central.
Lead singer and composer Laila Skoymand wanted to find a way to sing underwater and she tried out her first experiment by singing while submerging her mouth in a kitchen bowl filled with water. At the time the bubbles added to the pop sound of the music.
She now has a technique mastered which enables her to hit the high notes - she holds an air bubble in her mouth to sing through it while submerged in water. She has to rise above the water once every minute to take a fresh breath and collect a new air bubble.
But due to the small amount of air in the bubble, Laila can only make short, high-pitched tones because lower tones are created more nasally.
Laila added: "There is also a technique where I switch between singing on the exhale and inhale. But it can be hard to control."
Laila discovered only stringed instruments would work in water, and she would need to actually invent new instruments if she wanted to set up her own underwater band.