Music happens five times,
and only one of them is dancing.

Music is not one job on the day, it is five: guests arriving, the ceremony itself, the drinks afterwards when nobody is sitting down, the meal, and the dancing. Each has a different job to do, and a playlist that works beautifully for one will actively damage another. The arrival is background with a purpose. It fills a room that would otherwise be silent, and it tells people something is about to start.

The drinks hour is the loudest of the quiet parts. Everyone is standing and moving between groups, so the music has to sit under all of that without disappearing into it, and this is the moment for the songs you love that nobody else knows. The meal is the opposite discipline. Dinner music should be close to invisible, and the test is simple: nobody at the table can name what is playing, because everyone is talking.

Anything with a chorus people recognise turns half the room into an audience and stops the conversation you spent weeks building a seating plan for. The dance floor then reverses it again. Familiarity is the whole point, because people dance to songs they can sing rather than songs they are hearing for the first time, and your favourite obscure album track will empty a full floor. Play that one during the drinks, where being unknown is a virtue.

Ceremony music is the part with constraints attached, and they are rarely written anywhere you would think to look. Many venues and most places of worship have a view on what may be played: some restrict recorded music entirely, some allow it only at certain points, some rule out anything with secular lyrics. In some places that is a house rule, in others a condition of the licence the building holds. The officiant or the venue coordinator will know, and the question takes one email.

Ask early, because the answer changes what you are choosing from, and because a live musician needs the piece well ahead of the day. A quartet, an organist or a singer will not sight-read your arrangement on the morning. Several weeks is the honest minimum, and anything that has to be arranged or transposed needs considerably longer. Send the exact recording you have in your head rather than just the title, because two versions of the same song can be four minutes apart.

The ceremony usually needs three pieces and people remember two: the entrance, the middle while a register is signed or a reading is prepared, and the walk back out. The middle one has to stretch, because signing takes exactly as long as it takes, and a two-minute track that ends while everyone is still standing about leaves a small, avoidable silence. Instrumental music solves it, and so does a musician who can simply keep playing until you are ready.

A band is an event in itself. People watch a band in a way they never watch a DJ, and the costs are practical rather than musical: floor space, a load-in slot, power, somewhere to change and something to eat. It plays in sets with breaks between them, so you also need a plan for the breaks. And its repertoire is its repertoire. Ask months ahead for anything that is not already on the list, and expect to be told no to some of it.

A DJ reads the room, and that is what you are actually paying for. Not a music library, which anybody can assemble, but a person watching who is dancing and choosing the next record accordingly. A good one will quietly ignore your running order at the right moment, because the floor is full and stopping it would be vandalism. So give a DJ direction rather than a script: the shape of the evening, the must-plays, the never-plays, and then let them work.

A playlist you run yourself is exact and completely inflexible. It plays what you chose in the order you chose it, which is perfect for the arrival and the meal and unforgiving on the dance floor, because a laptop cannot see that the room emptied four songs ago. Put somebody else in charge, with the device, the volume and explicit permission to skip. Build each of the five moments as its own list, and plan for what software ignores: the speech that runs long, the cable, the battery.

Three minutes is longer than it sounds. Stand in your kitchen with a timer and dance to a whole track with nobody watching, and you will understand at once why couples cut it. Most recorded songs run between three and four minutes, and on a cleared floor with every guest looking at you, the last minute of that is a long stretch to fill if you have not decided in advance what happens in it.

There are two normal ways out. Cut the track, with a clean fade at around a minute and a half to two minutes, edited beforehand and handed over as a file rather than decided by somebody reaching for a laptop on the night. Or keep the whole song and have the room join you partway through: the parents at the end of the first verse, the wedding party after that, everyone by the last chorus. Tell those people beforehand so they actually move, because if nobody has been briefed, nobody wants to be first.

Either way, the person playing it needs the exact version, and needs to know where it starts and where it stops. The album cut, the live recording, the remaster with the long instrumental opening: as far as the day is concerned, those are different songs. A first dance that begins with forty seconds nobody expected only becomes funny later.

The request slip on the table is a tradition worth retiring. It produces handwriting nobody can read, arriving in ones and twos across the whole evening, at the hour the DJ is busiest, and many of them land long after the floor has settled into something that was working. Asking in advance costs your guests the same thirty seconds and gives you a different object entirely: one list, in front of you, weeks before anyone arrives.

You also get better songs. Someone thinking about it on a train, unhurried and sober, remembers the record that was playing in the car on the way to your first flat. The same person at half past ten with a pen and a napkin writes down whatever is in the charts. Reading the list beforehand also means you can see what is coming: the joke request, the six people who all asked for the same thing, the song that would land badly in front of one particular table.

In Vowly the question sits on the same event page your guests already open for the schedule and the RSVP. They suggest a song while they are replying, and you watch the list build up in one place, in whichever of the nine languages they are reading the page in. Nothing plays automatically and nothing is linked to anybody's music account. It means the band or DJ gets one document a fortnight ahead instead of forty interruptions at the booth, and can tell you which requests they already have and which one will empty a full floor.

Everyone writes the list of songs they want. Far fewer write the list that actually protects the evening: the songs that must not be played under any circumstances. A professional fills gaps competently without your help, so a long must-play list is mostly a comfort to you. The do-not-play list is the only thing standing between the room and the song that was played at somebody's funeral in March.

Keep it short and specific enough to act on. Titles and artists, not moods. If a whole genre is out, say so plainly in one line. Include the ones that are obvious to you and completely invisible to a stranger: an ex's song, a track tied to a bereavement, the one that will restart an argument between two branches of the family you have been careful to seat apart. Nobody needs your reasons, and the list works without them.

Then put it in writing, in the same document as everything else, and confirm that it has been read. A do-not-play list mentioned once in a phone call in March does not exist in September. If you are running the music yourself, the same list goes to the friend with the device, along with the authority to stop a track halfway through when a guest gets hold of the machine.

Older guests usually do not leave early because they are tired. They leave because they cannot hear the person sitting opposite them, and an evening of nodding at half-understood sentences is exhausting in a way that being tired is not. Hearing loss makes speech very hard to pick out of background music long before the music feels loud to anybody else in the room, so by the time you notice, they have been struggling for an hour.

The one change that keeps them in the room is a quieter room to go to. Not the corridor and not the smoking area, but a lit, seated space next door with the music turned right down, where three generations can sit and talk while the dancing carries on through the wall. Ask about it when you book the venue, because it is a room-allocation question rather than a music question, and far easier to answer months ahead than at nine in the evening.

Then agree a level. Ask the band or DJ to hold the volume down through the meal and the speeches and to bring it up when the dancing starts, so the loud part of the evening is genuinely loud and genuinely short rather than constant. Give one person, not you, explicit permission to say that it is too loud. On the day you will be somewhere else, and a room of people who are each slightly uncomfortable will say nothing at all.

Send one document, about two weeks before, to everyone who will be playing music. It carries the running order with real clock times: the ceremony, the meal, the speeches, the first dance, the last song. The names of anyone who gets announced, spelled out phonetically if they are easy to mispronounce. The first dance track, with the exact version and where the cut falls. The guest requests. The do-not-play list. And the time the music has to stop.

The finish time is the item most often left out and the one with money attached to it. Venues have a hard curfew, and the difference between the music ending at midnight and at one is a licence condition, sometimes a noise limiter that cuts the power on its own, and usually an extra fee. Find out the real number, tell the band, and decide now what the last song will be rather than at ten to midnight with a queue of requests.

Everything in that document already exists somewhere else in your planning: the order of the day, the guest list, the names, the requests. Keeping it in one place is the whole point of a wedding planning app, because the schedule your guests read and the running order your DJ works from are the same set of facts. Move the ceremony half an hour and it should not have to be remembered separately in five conversations. If you have not fixed those timings yet, the order-of-the-day guide has the hour-by-hour version.