Poets are not necessarily, music composers. Neither can fit the role of musicologist. It will be better to have a separate section for musicologists. Many eminent names of CM ,from pre-Trinity and the last century come to mind. like Govindha Dikshithar, Venkatamakhi, and the later Govindacharya of the current 72 MK system , the author of SSP, Prof.Raghavan, Prof.Sambamurthy, Sri.T.K.Govinda Rao, Sri.T.V.Subbarao come to mind.
There was a nice article about Govinda Dikshithar in the Music academy journal of 1995.
GOVINDA DEEKSHITA SAVANT & MUSICOLOGIST
N.K. VENKATESAM PANTULU
though very little about the musicology of the great man. Nevertheless, very interesting and fixes the time frame at 1550, immediately after Purandaradasa. Shows the continuity of tradition from 1500 AD to 1900 AD.
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A much better blog post with focus on Govinda Dikshitar as a musicologist is available in
https://sreenivasaraos.com/tag/govinda-dikshita/
(Look for section 13)