Between breakfast, study hall, and lunch today Seamus Finnigan made his rounds to the individuals who mentioned that they were interested in having a
listening party. He acted pretty casually and it wouldn't have been out of the ordinary for him to be seen with most of these people. He would have provided them with a galleon and explained,
"Consider this your entry token." He would not have told anyone what the galleon was for - just bring it. He would have told everyone they'll meet,
"You know where we've hung out before? Show up around 5:45...6-ish." Any questions about what the broadcast was would have been met with,
"Your guess is as good as mine, mate. I'm just the key provider.".