Siri went by herself, mostly curious as to what sort of music they would play. Of course, nothing from her home galaxy, but she liked it very much anyway.
Iroh came to keep an eye on his kiddos, and of course brought tea that he kept toasty warm for anyone that wanted some.
Diana also came to listen, would have brought Arthur if he was free, and also Donna if she wasn't being too sad.
Poe convinced someone (probably Arthur) to wear his portable emitter so he could do some people watching, his favorite pastime.