Good question.

Depends if I'm performing in a folk music concert setting (including festivals) or if I'm working in a pub.

for concerts:
1. Agree with you. Open with a strong number that has a catchy tune, not too fast, but still uptempo;
2. follow it with another uptempo song, perhaps one that has some humour, get people relaxed and settled in;
3. Third song is a tough one. Something a bit more serious in content, but not a slow one;
4. If instrumentals are part of the show, then an instrumental that is really upbeat and gets people tapping their feet;
5. Time to bring it down, you can slow it down and do a very serious song.
6. You can follow with another serious and slower song, but intersperse some commentary, perhaps a joke to offset the seriousness of the song. Song lyrics speak for themselves and can make the point and humour or stories can break up two slow or two serious songs in a row.
7. follow that pattern. The last song of a set should be uptempo, perhaps one of your best instrumentals or most powerful songs to get people to come back after intermission. It's also the way to end an evening so that they want more and ask for an encore.
By the way, always have a song ready for an encore.

It's fine to sing several slow or serious songs in a row, but change the key, not exactly the same tempo and not be afraid to tell stories, add some funny. People need that break, otherwise it can become unrelentless.

Another thing to consider - introducing songs. When I first started some of my introductions were very long - too long. I've cut them down just enough to set the stage for the song. Other times, as I said before, songs speak for themselves, they need no introduction. I've done that towards the last half of a set. I play a fast instrumental and when I end I pause for a few seconds and sing something like Warshaw's "No Time for Love" which is a powerful song, very serious. At the end of that song there's usually a few seconds of silence as people catch their breath and then applaud. By that time they want something livelier, a little lighter.
I usually sing the deathly serious numbers as either second last or third last number in a set because I want to end the sets on a high note.

The other thing I try and do is work off of themes. I usually try to construct a song list where I can interweave the thoughts of the songs , and that can be done through the stories or commentaries between songs. What is it that links this music together? After two or three songs I can then make a break for "something completely different". I wouldn't sing three prison songs or songs about miners in a row (perhaps two and leave the third for the second set).


On the other hands, pubs:
1. Start off with something catchy, something the audience has heard before just to get their attention;
2. follow it up withanother quickpaced song, different key. Trick for concerts and pubs - if you're going to play two songs in the same key then make sure there's enough of a pause, strum your guitar between the two songs in a different key. In my case I run a few notes on the accordion, or strike a different chord and appear as if i setting up for another song.
3. Third or fourth song can be slow.
4. Follow it up with an instrumental if possible.
Too many musicians who I perform see the audience in a pub scene as young and energetic and so keep up a relentless fast paced high volume set. I tell them that it's ad for the audience and bad for the musician. You jst can't keep up that pace all night. What you want to do is bring the audience up and up and up, and then you bring them down with a slow song or ballad. They gain a greater appreciation for the nuances of music that way and it doesn't kill you in the performance.

Len Wallace