The German conductor's fourth piece cut by Hallé, without everything getting spoilt (6)
I believe the answer is:
dashed
'spoilt' is the definition.
(dash can mean to spoil or destroy)
'the german conductor's fourth piece cut by' is the wordplay.
'the german' becomes 'das' ('the' in German).
'conductor's fourth' becomes 'd' (4th letter of 'conductor').
'piece cut' becomes 'he' (I am not sure about this - if you are sure you should believe this answer much more).
'by' is a charade indicator (letters next to each other).
'd' after 'he' is 'hed'.
'das'+'hed'='DASHED'
'halle without everything getting' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
(Other definitions for dashed that I've seen before include "Rushed headlong" , "Thrown down or ran fast" , "Sprinted, rushed" , "Frustrated" , "Jolly" .)