Circus acts are unusual - one’s bringing in the top people (10)

'circus acts' is the definition.
(people doing acrobatics in the air)

'are unusual one's bringing in the top people' is the wordplay.
'unusual' indicates anagramming the letters.
'one's' becomes 'I's' (Roman numeral).
'bringing in' is an insertion indicator.
'the top people' becomes 'A-list' (A-list).
'are' is an anagram of 'aer'.
'aer'+'is'='aeris'
'aeris' enclosing 'alist' is 'AERIALISTS'.