This can be incredibly easy or really difficult! Many couples argue about the choice of first dance song not realising that there are in total around 8 or so songs that you need just for the ceremony part of the day!! So here's my quick guide on what you'll have to plan for when it comes to music.
Pre-Ceremony
Bridal and groom prep is the part of the day when you're relaxing and hanging out with your favourite people getting your hair and make up done, or going out for breakfast. I've done weddings where they've watched movies in this time, played music on the music channels on TV, or had quiet, and from my opinion the best has always been just a phone with great music plugged into a speaker of some sort. If you have a TV on then people get distracted too easily which makes for tricky photos! So if you want to create a vibe in the morning, get a playlist of funky tunes together that builds the buzz in the room.
Guests generally will arrive around an hour to 30 mins before your ceremony starts and depending on the venue there may need to be music while they wait. Once they're getting seated, usually 30mins before ceremony, you will need to have some music to set the scene. So it can be pre-recorded or you might have something like a string quartet.
Ceremony
For this part of the day you need about 5 or so tracks. So, one or two for walking down the aisle (how many will depend on how many people you have walking in and if you want to change the music for the bride to walk in on her own tune), three for the signing of the register part of the ceremony as this can be quite boring for guests to sit and watch you sign a book (one of my couples had someone from the guests sing which was lovely - she was a singer so it was beautifully done!), and then you need your exit song! And of course you need to make sure that your ceremony venue will allow the song you choose.
Reception
Once you've been legally married and you're relaxing with your guests, you will need music while people chill and eat canapes or their sit down lunch. I've seen a range of live music to pre-recorded, anything works really. If people are eating then you want something that's background music and not too loud.
Evening
Ahh first dance and after party! And if you can't decide which song to have a first dance or you both have a favourite, then why not have two!! When I got married we loved two songs but couldn't decide which to have so we started with a nice slow intro dance with Etta James "At Last" and then the DJ at a prime point in the song changed over to Michael Buble's "Christmas (Baby Please Come Home)" and we had a fun boogie to a snow machine! The guests and the kids loved it!
Most DJs will also ask you for a list of songs to play in the evening at the party or a general idea of what you and your guests would like. On your RSVP you can also include a line for guests to request a favourite song and then pass this list to the DJ.