phrase

[Zappaterra]

Where did the phrase Be There or Be Square come from

[Clanad]

Meaning, you should be at a certain place or participate in a certain activity or be considered un-cool.  Most likey American in origin arising in the late 1940's to mid 1950's when "square" came mean un-cool, not with it, an outsider, not one of the clique, etc. Especially captured in the 1955 James Dean movie, Rebel Without a Cause...wherein being square was the worst possible fate that could befall a teenager...