Rank ratings given by old music-maker (8)
I believe the answer is:
absolute
'rank' is the definition.
(synonyms)
'ratings given by old music-maker' is the wordplay.
'ratings' becomes 'abs' (I've seen this before).
'given by' means one lot of letters go next to another.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'music maker' becomes 'lute' (lute is a kind of musical instrument).
'abs'+'o'+'lute'='ABSOLUTE'
(Other definitions for absolute that I've seen before include "Complete, full" , "Sheer - unqualified" , "Total or final" , "Unconditional, downright," , "Complete or not limited" .)