The custom of playing kite flute during the Sao Den Kite Festival has been recognised as a National Intangible Cultural Heritage. (Photo: zing.vn)

The festival, which takes place in Song An Commune, in the northern province of Thai Binh, is one of the region's major events.

The commune is also home to the Sao (Flute) Temple – a national historic and cultural site, which hosts the Sao Temple Kite Festival annually.

Visitors to the Temple can see a 400-year-old kite flute hanging above the solemn main altar – evidence that the locals regard the kite as a significant spiritual source. The one-week festival, held from the 18th to the 28th day of the third lunar month, draws dozens of kite flute fliers and thousands of visitors from neighbouring areas.

Alongside a parade of the Queen Mother’s palanquin, the festival also features several contests or folk games such as cock fighting, swimming to catch ducks, and walking on a slender bamboo trunk supported by ropes over a pond.

The kite flute competition is the most anticipated event of the festival with many kite flyers from the region participating.

The kite should measure at least 1.8m to be able to carry a flute made of bamboo and jackfruit wood, which is lighter than other kinds of wood.

While a single kite flute produces only bass tones, a multiple flute kite can create various tones like an orchestra.