Hamsadhvani (meaning "the cry of the swan"^[1]), is a rāga in Carnatic music (musical scale of Carnatic tradition of Indian classical music). It is an audava rāgam (or owdava rāga, meaning pentatonic scale).^[2] It is a janya rāga of the Melakartha raga, Sankarabharanam (29th) but according to Hamsadhvani's prayoga or the way it is sung it is said to be the janya of Kalyani (65th).

Hamsadhvani is also extensively used in Hindustani music and is borrowed into it from Carnatic music.^[3] It was created by the Carnatic composer Ramaswami Dikshitar (1735–1817),^[4] father of Muthuswami Dikshitar (one of the musical trinity of Carnatic music), and brought into Hindustani music by Aman Ali Khan of the Bhendibazaar gharana. It has become popular due to Amir Khan.

Hamsadhvani does not contain madhyamam or dhaivatham. It is a pentatonic scale (audava-audava ragam^[3][5] in Carnatic music classification – audava meaning 'of 5'). Its ārohaṇa-avarohaṇa structure (ascending and descending scale) is as follows (see swaras in Carnatic music for details on below notation and terms):

• ārohaṇa : S R₂ G₃ P N₃ Ṡ^{[lower-alpha 1]}
• avarohaṇa :Ṡ N₃ P G₃ R₂ S^{[lower-alpha 2]}

The notes used in this scale are shadjam, chatushruti rishabham, antara gandharam, panchamam and kakali nishadam. In Hindustani music, it is associated with Bilaval thaat (equivalent of Shankarabharanam).

Hamsadhvani rāgam lends itself for elaboration and exploration and has many compositions in both classical music and film music. It is usually sung at the beginning of a performance.^[3] There are many kritis (compositions) in praise of Lord Ganesha set in this musical scale.

• Jalajaskhi an adi Talam Varnam
• Gajamukhane Siddhidayakane by Vyasatirtha
• Raghunāyaka,Śrī Raghukula and Abhishta varada by Tyagaraja in Telugu
• Vātāpi Gaṇapatiṃand parvathypathim by Muthuswami Dikshitar in Sanskrit
• Pāhi Śripatē by Swathi Thirunal Rama Varma
• Varanamukha vā by Koteeswara Iyer
• Mūlādhāra mūrti, Karunai seivai, ullam irangi and parasakthi janani by Papanasam Sivan in Sanskrit and Tamil
• Gajavadana beduve by Purandaradasa in Kannada
• Nammamma Sharade by Kanakadasa in Kannada
• Vināyakā by Veena Kuppayyar in Sanskrit
• Varavallabha Ramaṇa by G. N. Balasubramaniam
• Gaṃ Gaṇapatē by Muthiah Bhagavatar
• Pirai Aniyum Peruman by Dr M. Balamuralikrishna
• Vinayaka Vighnavishaka by R Ganapati
• Sundar Gopālaṃ by Devaki Pandit
• Varuvai Arulvai Shantanayagi by Manachanallur Giridharan
• Tumbikkai Andavane by Manachanallur Giridharan
• Vinayaka Ninnu Vina by E.V. Raamakrishna Bhaagavatar
• Vande Anishamaham by Mysore Vasudevachar
• Bhajamahe Sree Vinayakam by Tulaseevanam
• Arul purivai and Karunai seiguvai by Sudhanandha bharathy

• Lagi Lagan Pathi Sakhi Sangh from the movie "Meghe Dhaka Tara"