The drums, cast in bronze using the lost wax method, are up to a meter in height and weigh up to 100 kg. Dong Son drums were apparently both musical instruments and cult objects. They are decorated with geometric patterns, scenes of daily life and war, animals and birds, and boats. The latter alludes to the importance of trade to the culture in which they were made, and the drums themselves became objects of trade and heirlooms. More than 200 have been found, across an area from eastern Indonesia to Vietnam and Southern China.
In 1902, a collection of 165 large bronze drums was published by F. Heger, who subdivided them into a classification of four types.
The Heger 1 drums of the Dong Son culture were classified and divided into five groups by the Vietnamese scholar Pham Huy Thong in 1990, a division that implied a chronological succession. The earliest, group A, comprisees a set of large and intricated decorated drums. Group B consists of a smaller drums who almost universally have a group of waterbirds in flight as their key motif on the tympanum and the mantle designs. Group C has a central panel on the tympanum made up of a row of plumed warriors placed inside another panel of waterbirds in flight. Toads line the tympanum's edge while the mantle was decorated with either patterns involving boats or geometric patterns.
The Hoang Hoa drum is a notable specimen of the Dong Son culture of the Bronze Age that existed in the Red River Delta in approximately the first five centuries BCE.
It was discovered in Ha Son Binh Province in 1937, with an outer panel of crane egrets and an inner panel which shows a procession similar to that described in the Ngoc Lu drum, the most famous of the Dong Son drums.
The drum shows a procession similar to that described in the Ngoc Lu drum, the most famous of the Dong Son drums. This drum varies in that it depicts four sets of men in procession with feathered headgear, rather than two. Also, each set comprises three or four people none of whom appear to be armed. The posture of the men was interpreted as that they were participating in a dance rather than a military ceremony. In this drum, only one pair of people are depicted as threshing rice, and there is no cymbal player. However, the general motifs, such as the boats on the mantle, remain in place.
Large drums found in northern Vietnam were generally in the minority, as most drums have simple decorations with fewer representations of people. The Ban Thom drum has only an inner panel comprising of four houses and plumed humans standing alone or in couples.