Here's something that may be of use. According to page 118 of the act (page 129 of Acrobat) indoor sports will need licensing. I've added the relevant text below:-

Indoor sporting events

16 (1)An "indoor sporting event "is a sporting event —
(a)which takes place wholly inside a building,and
(b)at which the spectators present at the event are accommodated
wholly inside that building.
(2)In this paragraph —
"building "means any roofed structure (other than a structure with a
roof which may be opened or closed)and includes a vehicle,vessel
or moveable structure,
"sporting event " means any contest,exhibition or display of any sport, and "sport " includes —
(a)any game in which physical skill is the predominant factor,
and
(b)any form of physical recreation which is also engaged in for
purposes of competition or display.

So you see , any pub which is going to hold a contest for darts, pool, skittles and the such like should seriously think about including live music, as they're going to have to tick the box for indoor sports anyway. Also for unamplified music there is the following which could help sessions etc as the council cannot impose onerous conditions. It can be found on page 100 of the act (page 111 of Acrobat):

Dancing and live music in certain small premises
(1)Subsection (2)applies where —
(a)a premises licence authorises —
(i)the supply of alcohol for consumption on the premises,and
(ii)the provision of music entertainment,and
(b)the premises —
(i)are used primarily for the supply of alcohol for consumption on
the premises,and
(ii)have a permitted capacity of not more than 200 persons.
(2)At any time when —
(a)the premises —
(i)are open for the purposes of being used for the supply of alcohol
for consumption on the premises,and
(ii)are being used for the provision of music entertainment,and
(b)subsection (4)does not apply,
any licensing authority imposed condition of the premises licence which relates to the provision of music entertainment does not have effect,in relation to the provision of that entertainment,unless it falls within subsection (5)or (6).
()Subsection (4)applies where —
(a)a premises licence authorises the provision of music entertainment,and
(b)the premises have a permitted capacity of not more than 200 persons.
(4)At any time between the hours of 8 a.m.and midnight when the premises —
(a)are being used for the provision of music entertainment which consists
of —
(i)the performance of unamplified,live music,or
(ii)facilities for enabling persons to take part in entertainment
within sub-paragraph (i),but
(b)are not being used for the provision of any other description of
regulated entertainment, any licensing authority imposed condition of the premises licence which relates to the provision of the music entertainment does not have effect,in relation to the provision of that entertainment,unless it falls within subsection
(6).
(5)A condition falls within this subsection if the premises licence specifies that the licensing authority which granted the licence considers the imposition of the condition necessary on one or both of the following grounds —
(a)the prevention of crime and disorder,
(b)public safety.
(6)A condition falls within this subsection if,on a review of the premises licence — (
a)it is altered so as to include a statement that this section does not apply to it,or
(b)it is added to the licence and includes such a statement.

Aren't our lawmakers wonderful people