Music Theory/Indian/Gāndhāra

Gāndhāra/Gandhar/Gandhara is the 3rd Svara from the 7 svaras of Hindustani music and Carnatic music. Gandhara is the long form of the syllable ग. For simplicity in pronouncing while singing the syllable, Gandhara is pronounced as Ga (notation - G). It is also called as गान्धार or गंधार.

More information and importance of Gandhara

The following is the information about Gandhara and its importance in Indian classical music:

Gandhara is the third svara in an octave or Saptak.
Gandhara is the immediate next svara of Ṛiṣabha (Re).
The svara of Gandhara is Komal and Shuddha.
It is said that Sadja is the basic svara from which all the other 6 svaras are produced. When we break the word Sadja then we get, Shad And Ja. It means that Shad is 6 and ja is 'giving birth' in marathi. So basically the translation is :

 षड् - 6, ज -जन्म . Therefore, it collectively means giving birth to the other 6 notes of the music.

So the svara Ga is formed from Sadja.

The frequency of Gandhara is 300 Hz. The frequencies of the 7 svaras are also given below: Sa 240 Hz, Re 270 Hz, Ga 300 Hz, Ma 320 Hz, Pa 360 Hz, Dha 400 Hz, and Ni 450 Hz, Sa 480 Hz (Taar Saptak) ........ (and so on).

Consequently, the Ga after the Re of 540 Hz (Taar Saptak) has a frequency of 600 Hz i.e. the double of the Lower octave Ga.

There are Shruti's of Gandhara. Previously the main Shruti, not only for Ga but for all the other svaras, was on the last Shruti but now it is considered to be on the 1st Shurti.

For example, if these are the 2 Shruti's of Ga then,

                 Previously this was the position of the main Shruti of Ga.
                 ^ 
             1   2
             ^
             But now this position has become the main Shruti of Ga.

All the other svaras except Sadja(Sa) and Pancham (Pa) can be Komal or Tivra svaras but Sa and Pa are always Shuddha svaras. And hence svaras Sa and Pa are called Achal Svaras , since these svaras don't move from their original position. Svaras Ra, Ga, Ma, Dha, Ni are called Chal Svaras, since these svaras move from their original position.

    Sa, Re, Ga, Ma, Pa, Dha, Ni - Shuddha Svaras
   
    Re, Ga, Dha, Ni - Komal Svaras 
  
    Ma - Tivra Svaras

Ragas from Kafi That, Asavari That, Todi That and Bhairavi That, have Komal Gandhara.
Ragas where Ga is the Vadi svara - Raga Kafi, raga Bageshri, raga Bhoopali etc. Ragas where Ga is the Samvadi svara - Raga Sohni, etc.
Hypothetically speaking, Ga is said to be the Gandharvas, Gandharvas as in, the three main gods, Bhrama, Vishnu and Shiva were first created i.e. Sarkar (Sa) and then these three gods created Rishimuni i.e. Re and then Gandharvas were created for singing. Ga is made the acronym of Gandharvas for showing the importance of the syllable Ga.
Gandhara is said to be sourced from the bleating of a goat.