Bands may contain additional persons not playing ukuleles provided that the number of such
persons does not exceed 50% of the number of ukulele players.
For clarification:-
a band of 4 people must have at least 3 people playing ukuleles,
a band of 5 people must have at least 4 people playing ukuleles,
a band of 6 people must have at least 4 people playing ukuleles,
a band of 7 people must have at least 5 people playing ukuleles,
a band of 8 people must have at least 6 people playing ukuleles,
a band of 9 people must have at least 6 people playing ukuleles,
etc.