He can always get Beethoven's fifth on the radio (4)
I believe the answer is:
seth
'he can always' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'beethoven's fifth on the radio' is the wordplay.
'beethoven's fifth' becomes 'h' (5th letter of 'beethoven').
'on' is a charade indicator (letters next to each other).
'the radio' becomes 'set' (I've seen this in other clues).
'h' put after 'set' is 'SETH'.
'get' acts as a link.
Can you help me to learn more?
(Other definitions for seth that I've seen before include "Biblical character" , "Adam and Eve's third son" , "Early human" , "Vikram --, Indian author" , "said to sound archaic" .)