Singer's failure not entirely dreadful, within concert series (10)
I believe the answer is:
troubadour
'singer's failure' is the definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'not entirely dreadful within concert series' is the wordplay.
'not entirely' becomes 'rou' (I can't explain this - if you can you should believe this answer much more).
'dreadful' becomes 'bad' (similar in meaning).
'within' means one lot of letters goes inside another.
'concert series' becomes 'tour' (I've seen this in another clue).
'rou'+'bad'='roubad'
'roubad' going inside 'tour' is 'TROUBADOUR'.
Can you help me to learn more?
(Other definitions for troubadour that I've seen before include "love poet" , "Minstrel" , "Medieval lyric poet" , "Mediaeval singer-poet" , "composer of lyrics" .)