Old instrument is superior to a modern one (5)
I believe the answer is:
viola
'modern one' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'old instrument is superior to a' is the wordplay.
'old instrument' becomes 'viol' (historical stringed instrument).
'is superior to' is a charade indicator (letters next to each other) (in a down clue, some letters go above others).
'viol'+'a'='VIOLA'
Can you help me to learn more?
(Other definitions for viola that I've seen before include "Page" , "Sebastian's twin (Twelfth Night)" , "Tenor fiddle - plant" , "part of a broken-down 27 [CARTHORSE]" , "Stringed instrument tuned lower than a violin" .)