For the purpose of making provision for those participating as performers in a
performance, or in a performance of a specified description, not to be
prevented from smoking if the artistic integrity of the performance makes it
appropriate for them to smoke—
(a) the power in subsection (1) also includes power to provide for specified
descriptions of premises or specified areas within such premises not to
be smoke-free in relation only to such performers, and
(b) subsection (3) does not prevent the exercise of that power as so
extended.