Gamaka (Hindi: गमक / Urdu: گمک) (also spelled gamakam) refer to ornamentation that is used in the performance of North and South Indian classical music.
The unique character of each raga is given by its gamakas, making their role essential rather than decorative in Indian music.
[4] Nearly all Indian musical treatises have a section dedicated to describing, listing and characterising gamakas.
For instance, those like Nayaki, Sahana, Devagandhari, Yadukulakambhodhi etc can never exist without key gamakas like kampita whereas ragas like Keeravani & Shanmukhapriya can sound acceptable with full or partial oscillations.
There can be considerable difficulty in conveying the complex and fluid melodic movement of gamakas in a notation system that uses fixed pitch signs.