Dhwani (Sanskrit) means sound of any kind. Out of all the Dhwanis created in the world, sounds that are 'musical'—give an experience or perception of a 'musical' sound—are called "Nadas". The sound of a 'clap' is a dhwani, but that of a bell is a nada. The commonest example of nada is a musical sound made on a stretched string under constant tension. There are innumerable 'Nadas' in a Saptak (Octave). Chaturdandi Prakashika (Sanskrit) by Pandit Venkatamakhin in Shloka 3, Chapter 2, stated that,