If you set the initial tempo in the playback control panel, use an expression to make changes to that tempo.

https://usermanuals.finalemusic.com/FinaleWin/Content/Finale/Tut6DynamicsArticulationsSlurs1.htm?Highlight=tempo%20expression

There are also video help files. Look in your program's Help menu.

Thanks, Mike, though not quite the straightforward answer I was hoping for, but I guess I will learn other things as well on the journey.

Specifically, though, the piece is set at crotchet/quarter note = 184.    I want to slow it to 120.    In the expression tool bar, yes, I see a metronome mark,. and can attach that in the right place, but it's showing the original 184 and I don't see where it offers me the opportunity to put in the new marking. Am I missing something?

In the expression Selection/Creation/Edit screen there is a Playback Tab that lets you choose a note value and set the Value of the Tempo.

(There are other ways of creating/setting tempo, but this is the simplest one to describe from scratch.)

That nearly works, Adrian. Thank you, BUT then it seems also to change the original tempo, which I certainly don't want!

Are you applying that expression to where you want the change to occur?

Take a look at the document I have put in my DropBox:https://www.dropbox.com/s/0z6m8hux9jcbof4/tempo%20test.musx?dl=0

Yes. But think I've solved it.   By hitting 'duplicate' on the existing "72 quarter note =184" in expressions, to create a copy, I then edited the copy to the desired speed = 120, effectively two different expression marks, then I get the tempo change I want - and if I wanted to change back I would simply select the original one.   And it works.   My only problem now is it wants to anchor to the first beat of the bar, whereas I want it on the upbeat at the end of the bar.   I suppose I could split the bars, but that makes it a little fussy!

You don't have to duplicate and edit. Just create a new one.

Use the Split Measure plugin. Split after 3 beats, invisible barline, Uncheck Move second part of Measure to next system.

https://www.dropbox.com/s/dzxap85lcqsf3ly/split%20measure%20tempo%20mark.musx?dl=0

Thanks Mike and Adrian.   I think I am there. Learning new things every day, no, every hour!   This pandemic does have SOME benefits!

On those occasions when I did not want a change of tempo at the barline, I went into the expression screen and used Edit Category to change the default starting position for a new tempo.

I learned something, too. Thanks, Adrian!

There are some pretty amazing secrets to be found in Finale (as well as obvious capabilities I keep forgetting), and I was lucky enough to stumble on this one when (like Matthew) I wanted to change tempo within a measure  (probably having something to do with setting a destination tempo for a rit. or accel.)

Very true, Adrian. I guess it's partly the difference between people who install the software and systematically go through (and learn?!) all the techniques and tutorials... and others (like me) who start working straight away and learn new tricks only on an 'as needed' basis. 

It may also have something to do with users (like Mike?) who have been using the software for years and years (decades?)

>I find the help files confusing and have really struggled with this<

Oh yea, you are preaching to the choir (and a few choir directors) on that one.

And here's another thing... extracting, say, 1st and 2nd flute to appear on a single pdf?   Yes; lots of chatter about linked parts, which I understand about the underlying (very clever!) architecture, but finding an answer to my question?   Is there one?

You already posted about this separately.

Hi folks, I am having the same problem, I want a changed tempo for the middle portion of the piece, and none of the responses are working for me (or I just don't know what/where you are talking about). I don't see where Matthew is when he is duplicating something "in expressions" - where is this? When I click on the Expressions tab, nothing happens. When I right-click on my metronome marking at the beginning of the piece, I get two choices basically: Edit expression assignment, and Edit Text Expression Definition. Neither of these get me anywhere. Every time I try to change one tempo setting, the other one (in the middle of the piece) changes too.

I don't understand any of the other comments, sorry.

What few ever post is that they downloaded something from the internet in MIDI or MusicXML, open in Finale and discover that Tempo ... just doesn't work must be a bug in Finale I don't understand helllllllpppp… and so on.

Hi folks, I am having the same problem, I want a changed tempo for the middle portion of the piece, and none of the responses are working for me (or I just don't know what/where you are talking about)

That!

It is imperative that you understand the hierarchy of tempo control as explained by Peter in this thread.

https://makemusic.zendesk.com/hc/en-us/community/posts/360001346534-Finale-ignoring-playback-speed

What does not matter is whether or not you agree with it—many don't and want it changed—but failure to understand how it works means that Tempo cannot be controlled the way you want— which is however you decide among the choices.

Now find my post in this thread where I explain how to clear MIDI so that the Expressions Tool or Playback Controls will work as advertised.

https://makemusic.zendesk.com/hc/en-us/community/posts/360001346534-Finale-ignoring-playback-speed?page=1#community_comment_360013892494 

Again, because of the hierarchy, if the Expressions Tool is controlling Tempo, the Playback Controls will not (just Start/Stop/Human Playback etc.).