Sequence of events arranged in a score (8)
I believe the answer is:
scenario
'sequence of events' is the definition.
(I've seen this before)
'arranged in a score' is the wordplay.
'arranged' indicates an anagram (letters rearranged).
'in'+'a'+'score'='inascore'
'inascore' with letters rearranged gives 'SCENARIO'.
(Other definitions for scenario that I've seen before include "Film treatment" , "Outlines of drama" , "Master plan" , "Imagined sequence" , "Iron case (anag)" .)