In Carnatic Music, Kalpanaswaram (also called swarakalpana (spelt alternatively as svarakalpana), manodharmaswara or simply swaras), is melo-rhythmic raga improvisation in a specific tala.
As part of swarakalpana, the musician delivers increasingly complex, improvised sequences in the Indian music solfege (sa, ri, ga, ma, pa, da, ni) within or towards the end of a composition.
The place where the first note of the first phrase of the composition exists in the rhythm cycle is called the eduppu.
Although there are no set rules, the artist may decide to expound the expressions of a particular raga in Kalpanaswaram as opposed to Alapana.
So with a raga like Sahana or Anandabhairavi, Purvi Kalyani, etc., which have Dhattu (jumping) swarams in their arohanam and/or avarohanam the Kalpanaswaram is harder to master and perform.