“a payment or transfer made for, [or] in respect of, or which in any way derives either directly or indirectly from the performance of the relevant activity has a connection of the prescribed kind with the relevant activity;” and in Regulation 6 prescribes the relevant activity: “(1) Subject to this regulation, any activity performed in the United Kingdom by an entertainer (whether alone or involving others) of any of the descriptions in paragraph (21 is an activity of a prescribed description ‘ relevant activity’) for the purposes of … these Regulations; (2) a relevant activity to which paragraph (1) refers is an activity performed in the United Kingdom by an entertainer in his character as an entertainer on or in connection with a commercial occasion or event…”