As we mentioned earlier, you could shell out hundreds of dollars to hire a DJ for your next event, or cut your expenses and use your MP3 player to play tunes instead. Music will be a key factor if your party is going to be a success, but only if guests respond to your song choices and dance the night away. To find out which tunes should make the cut, include a line on every RSVP card for guests to write their favorite song titles, or create an online poll to learn which genres of music will keep the crowd hopping. Depending on the formality of your event, you might need an emcee to announce things like the cutting of the cake at a wedding or the bar's last call at a class reunion. Simply rent the equipment you'll need -- like a microphone and microphone cable, sound mixer, amplifier, speakers and speaker stands -- for as little as $200 to $400 for the evening. Music should be the life of the party, so double-check all equipment in advance, and have a backup plan in case anything goes wrong!