TTR40020 - Qualifying productions: theatrical production
You should check the other guidance available on GOV.UK from HMRC as Brexit updates to those pages are being prioritised before manuals.
S1217FA & S1217FB Corporation Tax Act 2009
A production can only be a qualifying production for Theatre Tax Relief (TTR) purposes if it is a theatrical production: a dramatic production or a ballet, that is not specifically excluded by the legislation from being regarded as a theatrical production.
Dramatic production
A dramatic production means a production of a play, an opera, a musical or other dramatic piece (whether or not involving improvisation) in relation to which: