The tree, usually Pilla Maram (Jack Tree), is selected and cut to size to produce large wooden blocks about 20-25 inches in length and 10 inches in width and depth. The blocks are left, sometimes for years, to season.
The wooden block is roughly carved to shape of the Miruthangam with a hand axe. The shape has a wider area in the middle and narrow area to either side.
The small plane (10 x 10 inch) is marked, from the centre, on one side with a diameter of about 6 ½ to 7 ½ inches (Valanthalai – Right head) and the other side with a diameter of about 7 ½ to 8 ½ inches (Idanthalai – Left head).
The block is then fixed, at the centre of the edges, to the lathe, a machine that spins the wood at high speed allowing for precision carving. The block is roughly carved to shape.
The wooden block, spinning on the lathe, is then carved to perfect shape with a wood lathe chisel. The spinning action causes the chisel to cut the wood evenly. The central artistic markings are also made at this time.
The finly shaped wooden block is then taken off the lathe and different attachment is then applied that allows for hollwing out. Typically a long chisel afixed to a metal arm is used. This produces the frame, “Koddu”or “Koodu”, of the Miruthangam. The processes is the same for other instruments that have a wooden frame.
Creating the mootu
Circular leather pieces are fixed at either end with leather straps. Leather pieces are then weaved with leather strap around the frame to produces a circular membrane called the “Mootu”. The Valanthalai Mootu has a smaller hole on the top membrane and the Idanthalai Mootu has a larger hole on the first two membranes. Go to Structure explored for detailed breakdown of the Miruthangam.
Fixing the mootu
Both Mootu are then held to the Koddu with a long leather strap (16-18 meters in length). The strap is fixed to 16 holes on each of the Mootu and is platted around the Koddu. The straps are tightened, taking care not to exert extreme force that may cause the straps to snap.
Applying the soru
Soru or Saatham (paste made from a mix of iron powder and rice) is added to the Valanthalai Mootu in layers, each additional layer being smaller than the previous. Each layer is applied firmly and smoothed using a granite stone. The finished Soru on the Mootu forms a lump, reverse meniscus or hyperbola, type shape. For lower pitched Miruthangam the Soru is made thicker and for higher pitched Miruthangam the Soru is made thinner.
Finishing and fine tuning
The final step is to either place small pieces of straw (for Kutchi Miruthangam) or granulated Soru (for Kappi Miruthangam) between the outer layer and the Soru layer of the Valanthalai Mootu. Go to Types of Miruthangam to find out more about the two types. Once this is done the Miruthangam is tuned to the required pitch (leather straps may be further tightened or loosened) and the Chaapu Naatham is balanced (a small layer of Soru may be removed). The Miruthangam is now ready to be played on.