Turns out lutenist Martin’s one of the musical group (15)
I believe the answer is:
instrumentalist
'one of the musical group' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'turns out lutenist martin's' is the wordplay.
'turns out' indicates anagramming the letters.
'lutenist'+'martins'='lutenistmartins'
'lutenistmartins' is an anagram of 'INSTRUMENTALIST'.
Can you help me to learn more?
(Other definitions for instrumentalist that I've seen before include "musician" , "oboe, perhaps" , "one of the band" .)