An Avarohana, Avarohanam or Avaroha, in the context of Indian classical music, is the descending scale of any raga.[1] The notes descend in pitch from the upper tonic (taar shadja or Sa) down to the lower tonic, possibly in a crooked (vakra) manner.
Examples
In raga Darbari, an Asavari-thaat raga with vadi-samvadi R-P, the avroha is R' n S' d~ n P, m P g~ m R S, with andolan on the dhaivat and gandhar.
In Malahari, which is janya raga of 15th melakarta Mayamalavagowla, the avarohana is S D1 P M1 G2 R1 S.[1] See swaras in Carnatic music for description of this notation.
In Sahana, a janya raga of 28th melakarta Harikambhoji, the Avarohana is S N2 D2 P M1 G3 M1 R2 G3 R2 S.[1] This raga in its avarohana has the notes jumping from one to another (a bit like Dattu). This changes the whole feel of the raga, making Sahana a beautiful raga to listen to.