Organised tour around key house (5)
I believe the answer is:
tudor
'house' is the definition.
(royal house)
'organised tour around key' is the wordplay.
'organised' indicates anagramming the letters.
'around' is an insertion indicator.
'key' becomes 'd' (musical key).
'tour' anagrammed gives 'tuor'.
'tuor' going around 'd' is 'TUDOR'.
(Other definitions for tudor that I've seen before include "English royal dynasty" , "Mary" , "Architectural style" , "Pre-Stuart royal house" , "Dynasty's founder" .)