1. The smallest drum in the world created specifically as a musical instrument is likely the Piccolo Snare Drum by Dream Cymbals and Gongs. It stands at only 2.5 inches (6.4 cm) tall, with a 4-inch (10.2 cm) diameter.
2. The "Micro Snare Drum" created by UK craftsman Dave Drummond is also one of the smallest. It measures a minuscule 1.25 inches (3.2 cm) in diameter and is fully playable, with a fully tensionable snare system and a wooden shell.
3. From India, there's the Khanjira, which is a small frame drum with a goatskin head. The smallest Khanjira versions can have a diameter of about 3.5-4 inches (8.9-10.2 cm).
4. The African Udu is a small hand drum traditionally made from clay. In some of its smaller forms, the Udu can be about 4-5 inches (10.2-12.7 cm) tall.
5. The Native American Pow Wow Drum is another contender, with compact versions around 6-8 inches (15.2-20.3 cm) in diameter. These drums are typically adorned with intricate designs and are used for ceremonial purposes.
It's important to note that these are not official "records," as there's no definitive authority or body certifying the smallest drum. Different instrument creators and cultures have their own unique perspectives on what constitutes a drum and how small it can get while still being musically functional.