Sada Sat Simran Singh Khalsa is a member of Chardi Kala Jatha, and a Hazuri Ragi at Sri Harimandir Sahib, Amritsar. He lived in India for 15 studying Raga and Sikhism.
Here are some things he has to share on the subject of raag:
Raag is an ancient science from India. It started when the Rishi Munis were trying to communicate with angels. They used a melodic code to call on angels.
So how old is raag? It was written in the Vedas, and things written in the Vedas may have originated from thousands of years before they were even written. So raag is thousands of years old. Raag is always evolving. In the time of the Gurus (1490s to 1720s) the style of singing was Dhrupad. Dhrupad is a gradual and slow approach to music. It may have taken one hour just to complete one Shabad in this style.
How does raag work? Each raag has a specific combination of notes on a specific scale (mode) where you emphasize one particular note above the rest. There are also supporting notes. Each raag gives you a different experience, but each raag will give you an experience of bliss (Anand).
How to approach music? There are two approaches to things: devotion, Bhagti and power, Shakti. Bhagti takes time. Part of devotion is the concept of Sahej which means consistence, patience, and commitment. You do without any expectation or fatigue, company, time. You are in the moment. When you do raag with Sahej it becomes sweet. The catch-22 is that if you expect it, you don’t get the sweetness, but if you don’t expect anything you will get the reward.
Rishi Munis would do this for hours until their whole body resonated with that sound. To do this they would practice one rag for years. To do a Sidhi of a raag is a level of mastery where every cell of your being owns the raag.