Bob - Only going by what is written into the ASCAP and BMI (did not look at SESAC) Licensing.
Unless someone can show me a legal definition of a wedding under a tent that doesn't count as "any place where people gather" .. and please don't tell me that 100 relatives and work guests are somehow a "small gathering", HOW am I reading something into this? Unless you were doing it for free, how are you exempt?
ASCAP took some liberties with their paraphrasing of the actual law in their description. "small gathering" is not what the law says. Also, BMI states a "normal gathering" - not small. So as you see, even they gear their language to their benefit somewhat.
The actual law (again):
"To perform or display a work “publicly” means—
(1) to perform or display it at a place open to the public or at any place
where a substantial number of persons outside of a normal circle of a family
and its social acquaintances is gathered; or
(2) to transmit or otherwise communicate a performance or display of the
work to a place specified by clause (1) or to the public, by means of any device
or process, whether the members of the public capable of receiving the performance or display receive it in the same place or in separate places and at the
same time or at different times."
http://www.copyright.gov/title17/circ92.pdf
So a SUBSTANTIAL number of persons within your hypothetical wedding party of 100 would have to be outside a normal circle of a family and its social acquaintances. It has nothing to do with size. It has to do with a normal circle of a family - aka circle as in mother, father, daughter, son, grandkids, cousins, uncles, aunts, grandparents, in-laws, etc. Social acquaintances - that's a very broad net there - so there is no reason to think that a wedding of 100 persons would not fit into a normal circle of a family and its social acquaintances.