Composer has no clue, struggling at piano (7)
I believe the answer is:
poulenc
'composer' is the definition.
(I know that Poulenc is a composer)
'no clue struggling at piano' is the wordplay.
'struggling' indicates anagramming the letters (the letters struggle or wriggle into a new form).
'at' says to put letters next to each other (I've seen this in other clues).
'piano' becomes 'p' (musical abbreviation).
'no'+'clue'='noclue'
'noclue' anagrammed gives 'oulenc'.
'oulenc' after 'p' is 'POULENC'.
'has' is the link.
(Other definitions for poulenc that I've seen before include "He's composed" , "Francis -, twentieth century French composer" , "Francis ------- (1899-1963), French composer" , "French composer, d. 1963 - clone up (anag)" .)