Hey I was just wondering what kind of music you would play at a really big party? Well give me your opinion

Depends on the type of party. If there's a sit down dinner involved I would choose something like Frank Sinatra, Patsy Cline, Louis Armstrong. If it's just a free-for-all booze bash keep it upbeat. Depending on the age of your guests you may want to throw a few classic 80's and 90's songs in there. (People my age, 25-34, really dig that. It takes them back to their high school and college days.) You may even want to do separate areas for different music if it's a house party. (Dance room, chill out/conversation room, Karaoke, etc.) Just depends on you and your guest's style. Hope that helps.

I believe I would find out what kind of music the general crowed would like to hear.
For instance. You wouldn't want to play Metallica to a bunch of 90 year old people
They would be more into The big band era.

Celldweller, their debut self titled album... its great for weddings, 90th birthdays or a night on the town... just kidding its rock / heavy metal. But very good if you like rock music.

As said above, depends on the crowd and what type of music they like in general.