A raga is a pattern of notes – a combination of scales or melodies – used in Indian music; they are different to the familiar patterns of notes used in Western scale or melody. Each rag has (1) a particular ascending and descending pattern, and (2) is associated with a different time of the day, season, mood, or special occasion.
Raga are learned by imitating and memorizing. The music is passed on from teacher to student by oral tradition, students belonging to an extended family of musicians learning from a particular master. Most Indian classical music is based on a combination of rag (melodic form), tal (rhythmic form) and drone (sustained note). A system known as sargam is used for naming the notes: Sa, Re, Ga, Ma, Pa, Dha, Ni, Sa. The tonic, or ground note, is Sa; this is heard in the drone.