Singer featuring in musical today (4)
I believe the answer is:
alto
'singer' is the definition.
(alto is a kind of singer)
'in musical today' is the wordplay.
'in' says the answer is hidden in the clue.
'ALTO' can be found hidden inside 'musical today'.
'featuring' is the link.
(Other definitions for alto that I've seen before include "Unisex vocal range" , "Low female singing voice" , "Counter-tenor or contralto" , "Singer's hidden inside chemical toilet" , "Key old > male who scores high" .)