Main tempo disrupted in theatrical performance (9)
I believe the answer is:
pantomime
'theatrical performance' is the definition.
'pantomime' can be an answer for 'performance' (thesaurus). I am not sure about the 'theatrical' bit.
'main tempo disrupted' is the wordplay.
'disrupted' indicates anagramming the letters.
'main'+'tempo'='maintempo'
'maintempo' anagrammed gives 'PANTOMIME'.
'in' is the link.
Can you help me to learn more?
(Other definitions for pantomime that I've seen before include "Theatrical entertainment (usually at Christmas)" , "Cross-dressing theatrical" , "Farcical situation" , "farce" , "Traditional Christmas stage show with Dame" .)