Nagaswaram is a double-reeded instrument with a conical bore that flares out towards the bottom end. It usually consists of twelve holes of which the upper seven are used for playing. Wax is applied on the other holes (brahma swaram) to regulate the pitch. The reed is fixed on a metal staple and mounted on the top.

The length of nagaswaram varies from 2 to 21/2 feet and it is made of wood. It is covered with silver or gold. Spare reeds and an ivory needle with which the reeds are cleansed and adjusted, are attached to the mouth piece of the nagaswaram.

The nagaswaram of the south and the shehnai of the north are of the same family and in general appearance they look similar. Nagaswaram is also known as melam and olaga.

There are two varieties of nagaswaram. The big nagaswaram is usually called the bari type and the other is called timiri type. Nagaswaram is an outdoor instrument which is played on all festive occasions, processions and temple music. The music played on the nagaswaram is usually of a pure and serious type. It has great volume and power.