A composer of handy compositions (5)
I believe the answer is:
haydn
'a composer' is the definition.
(I know that Haydn is a composer)
'handy compositions' is the wordplay.
'compositions' indicates anagramming the letters (I've seen 'composition' mean this).
'handy' is an anagram of 'HAYDN'.
'of' acts as a link.
(Other definitions for haydn that I've seen before include "Classical composer" , "The Surprise symphony composer, d. 1809" , "Austrian composer of over one hundred symphonies" , "Barman" , "Joseph -, prolific eighteenth to nineteenth century Austrian composer" .)