Komal and Teevra Sur.

Out of these seven surs ,Re Ga Dh and Ni become “Komal”when their frequency is lower than their shudhha form.There place on the harmonium or keyboard is one note previous to their shudhha swar.

Among the seven basic swars,only one,that is Ma,becomes Teevra when its frequency is higher than its shudhha form and is placed next to the shuddha swar on keyboard.