Many notes after poor term, one's performance raised (8)

'many notes' is the definition.
The answer and definition can be both states of affairs as well as being plural nouns.
Perhaps they are linked in a way I don't understand?

'poor term one's performance raised' is the wordplay.
'poor' indicates an anagram.
'one's performance' becomes 'solo' (I am not sure about this - if you are sure you should believe this answer much more).
'raised' shows that the letters should be reversed in order (going up in a down clue).
'solo' written backwards gives 'olos'.
'term' anagrammed gives 'trem'.
'trem'+'olos'='TREMOLOS'

'after' is the link.

Can you help me to learn more?