Music is a very important part of your wedding. Determine if you will have the same individual musicians at your wedding that you heard elsewhere. Decide how many musicians will play. Also how many DJ's will be present. What kind of music they will play and who will act as Master of Ceremonies.
Some couples opt for a DJ for reasons of personal taste and lower cost.
Be sure to specify dress requirements for both the DJ and band members. Determine from their requirements if there is a need for special setups. The DJ's usually come prepared, however, sometimes they ask for table and cloths. Check your contract with them. Usually they request to be fed.