Singer featured in some of Waltons works (4)
I believe the answer is:
alto
'singer' is the definition.
(type of singing voice)
'some of waltons works' is the wordplay.
'some of' says the answer is hidden in the clue.
'ALTO' is hidden within 'waltons works'.
'featured in' acts as a link.
(Other definitions for alto that I've seen before include "Highest male voice: lowest female voice" , "someone to sing" , "Singer's hidden inside chemical toilet" , "Male singer" , "The highest adult male singing voice" .)