Ideas to include
A song the kids can sing
Name the children, borrow the things they say about their parent, and build a chorus small voices can shout back. It is the version that undoes the grown ups in the room.
The friends who go back furthest
The school nickname, the band they were in, the holiday from 1998. Give us the era and we let the old crowd hear themselves without losing everyone else.
The surprise party reveal
Tell us the room, the moment, and who is pressing play. We shape the opening so it works as the thing that stops the party dead.