The method of singing is called as Varna. There are 4 types of Varna:
1. Sthayee Varna: The method of singing one swar again and again by staying on it again and again is known as Sthayee Varna.
For example: Sa Sa Sa Sa, Re Re Re Re, and Ga Ga Ga Ga.
2. Aarohi Varna: the method of singing from lower notes to higher notes is known as Aarohi Varna.
For example: If we have to sing swar next to Sa then we sing (sa re ga ma pa dha ni) this is Aarohi Varna.
3. Avarohi Varna: The method of singing from higher notes to lower notes is known as Avarohi Varna.
For example: if we have to sing lower after swar (Sa) then we sing (śa ni dha pa ma ga sa) this is Avarohi Varna.
4. Sanchari Varna: when notes are mixed with the help of Sthayee, Aarohi and Avarohi Varna or in the other words when Sthayee, Aarohi and Avarohi Verna is combined then the method is known as Sanchari Varna.
Note: While singing or playing all the above four Varna are used.
In Indian classical music style of singing all the above 4 Varna are definitely there.