Different types of nada:
1. Unstruck sound
2. Struck sound
The unstruck sound connects directly to the Divine.
Struck sounds arise when two objects strike each other.
Naada -
It is made up of two sounds - na and da. 'Na' or Dakar, stands for life breath. And the 'da' sound stands for the fire element and energy. It is by coming together of these two forces that naada is born.
In the Sangeet Ratnakar,too, nada has been dealt with.
Many descriptive words are used for naada - like word, sound, voice, etc.
All the scriptures celebrate the glory of nada. For, whatever it may be - be it worship, life force, music or language, all are inhered by naada.
This is to establish that song, instrument, dance all function under the umbrella of naada. The whole universe transacts through naada because all languages arise from naada.
From naada arise primal sounds and from primal sound words come forth, from words sentences. And through sentences we express all emotions and thoughts.