Musical about six in the tea party (5)
I believe the answer is:
evita
'musical' is the definition.
(Andrew Lloyd Webber musical)
'six in the tea party' is the wordplay.
'six' becomes 'VI' (Roman numerals).
'in the' is an insertion indicator.
'party' indicates anagramming the letters (I've seen 'parties' mean this (the letters move or party around)).
'tea' is an anagram of 'eta'.
'vi' put inside 'eta' is 'EVITA'.
'about' acts as a link.
(Other definitions for evita that I've seen before include "Andrew Lloyd Webber musical set in Argentina" , "1996 musical film, starring Madonna" , "Well-known musical" , "Musical based on Argentine leader" , "Peron musical" .)