How to order a setlist
Open with something you can play cold, and close with the one they already know. In between, aim for a shape: a strong three to turn the room, a dip about two thirds in, and a lift you kept back. Most of what breaks a set is repetition the band cannot hear while playing it, and it shows up in the key and tempo columns before you leave the house.
There is no correct order. There are four ways to get one wrong, and they are all things a band cannot hear from the stage.
Open with what you can play cold
The first song happens with cold hands, a monitor mix nobody has heard yet, and a room that has not decided about you. Whatever needs a perfect vocal or a clean intro, that is not the one.
Open with something the band could play badly and get away with. Mid tempo or above, a part everyone knows without looking, nothing exposed at the top. You are buying two things. The engineer gets levels, and the drummer gets warm.
Your best song is not your first song. Play it third or fourth, once the sound is right and the room has turned round. Opening with it spends it on the two minutes nobody was listening properly.
Two songs in the same key is the mistake nobody hears
Two songs in a row in G, at similar tempos, sound to an audience like one long song with a gap in it. From the floor it is obvious. From the stage it is inaudible, because the band is busy playing.
It is not a rule against repeating a key. Half a bar band's repertoire lives in G, A and E, and you are not going to avoid it across twenty songs. What it is against is adjacent repetition, and the fix is nearly free: move one of them two slots.
Where the keys differ, the size of the jump does work for you. Up a tone or a semitone reads as a lift. A fourth up feels like arriving somewhere. A big unrelated jump reads as a stumble unless the tempo changes with it and makes it deliberate.
Do not try to hold that in your head. Read down the key column. The pairs sitting together are the ones to move.
Tempo is a shape, not a climb
The instinct is to start slow and build to the fastest song at the end. It does not work. Forty-five minutes of climbing has no contrast in it, so by two thirds through the room has stopped hearing the increases. Everything sounds like the same energy.
What works is a shape with a dip in it. Strong for the first three. Vary through the middle, fast and mid alternating rather than sorted. Then take it down properly for one, around 30 minutes into a 45-minute set, and come back up for the last two.
The dip is what makes the end feel like an end. Without it the last song is just another fast one. With it, the lift back up is the loudest thing in the set, and you did not have to play anything faster to get it.
Two thirds rather than halfway, because a slow song exactly in the middle splits the set into two halves that both sag. At 30 minutes it reads as the calm before the finish. At a median song length of 3:53, that is usually the tenth or eleventh song rather than the eighth.
Order around the gear, not just the songs
The list that looks best on paper is sometimes unplayable without dead air, and it is always for a physical reason.
A capo going on or coming off takes a bar or two. Between two songs that are meant to run together, that gap is the whole join, gone. Either move one song, or accept it and put the gap somewhere the singer is talking anyway.
A tuning change is worse. Anything in drop D wants to sit next to the other drop D songs, or somebody is retuning in front of a room. Two guitars solves it and most bar bands do not have two guitars.
An instrument swap needs cover. If somebody moves to keys, the song before it should be one where a few seconds of talking is fine, not the one where you were building momentum.
These are the constraints that make a real setlist differ from a good one, and they are why the order you play is rarely the order you would pick.
The second set is not the first set again
By the second set the room is warmer, drunker and smaller, and the people left are the ones who stayed for you. That changes the order.
You need less of a warm-up, because the band is warm and so is the audience. Open the second set nearer the energy you finished the first one on, not back at the beginning of the ramp. Save two songs everybody knows for the last twenty minutes, because that is when the floor either fills or empties.
How long that gap runs, and why it is never the ten minutes people say, is its own question.
Check the order on the sheet, not in your head
Every problem above is visible in a column. Adjacent keys, a climbing tempo, the slow one in the wrong third, a capo change in a gap that mattered. You can see all four at a glance on a list that carries the key and the tempo. None of the four announce themselves while you are playing.
Setlists.io fetches the key and tempo for each song when you paste the titles in, so the columns are already filled when you start moving rows. Reorder by dragging, watch the running time change as you go, and print it when the order is right.
Free, and it works without an account.