A new type of instrument created by musician, designer and engineer Dmitrii Gubarev based in the Ukraine. Appropriately called the Gubarev or GUDA drum, the first instrument sample was created by accident in 2013. While experimenting with the creation of reed drums, he noticed an interesting acoustic effect with the appearance of additional overtones while playing the instrument. Gubarev tried to enhance and strengthen these overtones using different methods until he achieved the results he wanted. He describes:
Technologically GUDA consists of two connected metal hemispheres made of stainless steel sheet 1.2 mm thick. The earlier production of GUDA models were made of high-carbon steel. In the center of the upper hemisphere is positioned 8 cm opening which serves to increase the sound volume. Semicircular reeds, located on the upper hemisphere, serve as the source of vibrations and sound. The lower hemisphere has no openings and serves to reinforce the resonance. While playing the GUDA you can find an interesting acoustic effect—one reed of the instrument produces two notes. In addition to the main tone, the reed performs additional sound one octave above. Thus, when you are playing the GUDA, to the characteristic “belfry” sounding of reed instrument, a kind of “steel pan” overtone is added. As a consequence, GUDA performs more complex timbre, as well as the volumetric and brighter sound. Also another interesting point is the use of harmonics while playing, which are extracted when struck just below the melodic lobe.Listen to some samples below and I think you'll agree that this instrument has a unique sound. You can purchase these drums at his Etsy shop or at his website.