Purnamadah purnamidham purnath purnamudachyathe
Purnasya purnamadhaya purnamevavashisyate
This Sanskrit verse explains the origin of OM Kara. It says, OM is infinite, it came from infinite. When infinite is subtracted from it, it remains infinite, such is its vastness!

From this all pervading, eternal Nada (sacred sound) of the Universe, of the God, creator of Nature “OM” emanated the seven swaras.Sources prove that the seven swaras are derived from the mother Nature(Universe) and each swara has its origin associated with the natural sound created by the divine animals .

1. Sa- Shadjamam - Cry of a peacock
2. Ri- Rishabham - Sound of an ox
3. Ga- Gandharam - Bleating of a goat
4. Ma- Madhyamam- Call of the heron
5. Pa- Ranchamam- Call of the cuckoo
6. Dha- Dhaivatham- Neighing of the horse
7. Ni- Nishadham- Trumpeting of the elephant

The seven swaras in varied combinations give rise to the twelve families of ragas, called the 12 chakras (According to Sampoorna Mela paddathi).Each of these12 families have 6 off-springs, that amounts to 12*6 =72 melakartha ragas, from which have originated hundreds and thousands of janya ragas.
1. Indu (Kanakangi,ratnangi,ganamurthey,vanaspathi,manavathi,thanarupi)
2. Netra (Senavathi,hanumathodi,dhenukanatakapriya,kokilapriya,rupavathi)
3. Agni (gayakapriya,vakulabharanam,mayamalavagowla,chakravakam,suryakantha,hatakambhari)
4. Veda (Jankaradwani,nathabhairavi,keervani,karaharapriya,Gowrimanohari,varunapriya)
5. Bana (Mararanjani,charukeshi,sarasangi,harikamboji,Dhira shankarabharanam, naganandini)
6. Rutu (yagapriya,ragavardhini,gangeyabhushani,vagadishwari,sulini,chalanata)
7. Rishi (salagham,jalarnavam,jhalavarali,navaneetham,pavani,Raghupriya)
8. Vasu (gavambodhi,bhavapriya,shubha panthuvarali,sadhvidha margini,suvarnangi,divyamani)
9. Brahma (Dhavalambhari,namanarayani,kamavardhini,Ramapriya,Gamanashrama,Vishwambhari)
10. Disi (Shyamalangi,shanmukhapriya,Simhendra madhyama,Hemavathi,Dharmavathi,Neethimathi)
11. Rudra (Kanthamani,Rishabhapriya,Lathangi,Vachaspathi,Mecha kalyani,Chitrambari)
12. Adithya (Sucharitha,Jyothiswaroopini,Dhatuvardhini,Nasikabhushani,Kosalam,Rasikapriya)

The raga in combination with the appropriate rasa would bring completeness to music.