Lyricist is a beginner, it's said (6)
I believe the answer is:
lerner
'lyricist' is the definition.
(lerner was an american lyricist)
'beginner it's said' is the wordplay.
'beginner' becomes 'learner' (I've seen this before).
'it's said' shows a homophone (sound like).
'learner' sounds like 'LERNER'.
'is a' is the link.
(Other definitions for lerner that I've seen before include "US lyricist" , "Musical librettist" , "4 1 [THANK HEAVENS FOR LITTLE GIRLS] writer" , "American lyricist" .)