Like modern flutes stars never replaced (10)
I believe the answer is:
transverse
'like modern flutes' is the definition.
(transverse flute is a type of flute)
'stars never replaced' is the wordplay.
'replaced' is an anagram indicator.
'stars'+'never'='starsnever'
'starsnever' anagrammed gives 'TRANSVERSE'.
(Other definitions for transverse that I've seen before include "Crossing" , "Extending across (the long axis)" , "Crosswise" , "go in 6 ac [CRISSCROSS]" , "Situated across something" .)