Take on song and dance part (5)
I believe the answer is:
adopt
'take on' is the definition.
(I know that take on can be written as adopt)
'song and dance part' is the wordplay.
'song and dance' becomes 'ado' (both can mean a commotion or fuss).
'part' becomes 'pt' (abbreviation).
'ado'+'pt'='ADOPT'
(Other definitions for adopt that I've seen before include "Take responsibility for" , "make one's own" , "Choose as one's own" , "Acquire" , "Foster" .)