Something like twenty years ago, sponsored by a local am radio, someone invented "La Noche de la Nostalgia" (the nostalgia night), to name a party where only "old hits" would be played. This party's idea spread along the years, like a virus, and now the night of the 24th it's a national phenomenon, that's even been passed as a law (LEY N° 17.825 ????).
This particular night moves as many people as the night of the 25th, or 31st of december. Some even say that it beats those nights, becoming THE night of the year when most people go out partying in Uruguay. It appeals to all ages, I know some old couples that only go out dancing that night in the year. There is a great variety of things to do, parties of all types and sizes, public, and private. Some people organize thematic custom parties. It's just different.
The whole thing is based in "the good all days" concept. The night of the 24th kinda celebrates the idea that former days of our lives will always be better than present ones, which sounds pretty much like a tango, if you think about it (todo tiempo pasado fue mejor). Here in Uruguay, nostalgia is culture.
It's speaks a lot about Uruguay's idiosyncracy. It's the yearly instance to remind us that we were once the champions of the world, we were called the switzerland of south america, and so on and so forth.
When it started old hits were music of the sixties and seventies, and now oldies mean eighties and ninties hits. If you go out you may listen to stuff like: Barry White, Barry Manilow, Air Supply, Billy Joel, Aha, Sui Generis, Los Shakers, Billy Idol, Queen, Beatles, Phil Collins, Michael Jackson, The Police, The Ramones, etc. There are also anti nostalgia movements, which organize rave parties to celebrate all the contrary, for those that cannot bear to live in a country that tends to look backwards, or that just want something different from that night.
The stay in the mood, I leave you now with an oldie...