Creating a set of music for a concert, theater, or movie all require different approaches. Much of deciding choices is a matter of experience. Choosing pieces for theater and movies is scene dependent and is complicated by requiring pieces that match the mood or action of the scene.
The simplest is probably setting a list for a concert or musical performance.
When choosing piece order, there are a number of things to take into account. These are not all the variables, but some examples:
- Key of each piece
- Tempo and/or rhythm of each piece
- instrumental arrangement
- lead vocalist
Key is one of the main considerations. It is probably better to avoid multiple pieces of all the same key/tempo/time all in a row. Keys of pieces can be arranged much like you would put together chord progressions. If you are transitioning from one major key to another major key, I've found that moving up seems to be an easier transition than moving down. For example, moving from D major to a piece in E major. I avoid downward motion because it seems to "drag" the feeling. Moving to the relative sub dominant or dominant is also effective. Switching to a minor piece is generally pretty easy, especially if going to parallel or relative minor of the previous piece.
Tempo of the pieces is another strong effect. Over the course of the set, smooth changes will be less jarring to the audience. You can, of course, have abrupt changes in tempo for effect. I generally try to avoid too many slow pieces in a row, and often ramp up the tempo then take a break with a slow piece.
The time of the pieces is also something you want to vary. A long string of all 4/4 time with the same under-rhythm is going to wear the audience out, although I've found that you can get away with the same rhythm for longer than things like key.
Instrumental and vocal arrangements can be broken up as well. Four pieces in a row with the same soloist or vocalist can create "too much of the same thing" in a set.
Once you have an idea of a set, it is a good idea to put it together and listen to it all the way through, either with recorded examples or a live run through. Multiple listens will show you where the set bogs down, or sounds too much of the same thing, where the rough transitions are. you can then "tune the set" from there.