28. How do I enable and disable the lead-in bars or count-in?

This is set in Band-in-a-Box^® | Preferences. If you want to hear the count-in, make sure that "Allow Lead in Bars" is checked, along with "Play Lead In even if Intro Present," and "Audible lead in." Also, check that the volume is turned up (64 is the default). Uncheck these options if you don't want to hear the count-in.

I have a related question.

I am using Mac version BIAB, all files use real drums and realrracks instruments.
When performing live, how do I lower just the volume of the lead-in clicks?
There is no reason for the audience to hear the lead-in clicks at full volume.

I have tried going to preferences, I have used various “Lead-in Type”, “Audible Lead In”
is checked, various instruments have been tried, and various Patterns have been selected.
I have set the lead in volume from 10 to 100 with no change in volume.
I have tried all of the above with “play” as well as “Generate and Play”,
with. frozen and unfrozen tracks....
still the lead-in volume does not change.

I'm not sure if the Mac version has the same feature-set for lead-in, but you could switch to a visible only lead-in like this:

Not possible... honestly, you really should know this by now (and that goes for all you well-meaning PC "experts" still blindly presuming what we Mac folks have been trying to tell y'all for years) - Not the same functions or options at all in that screenshot.

You wanna actually help? - then help us amp up the pressure on the PG team in our continuing battle to get ALL the same features & options you lot have in BBox (instead of seeing our complaints as some silly attack on you guys and get all defensive), since clearly there are just too few of us around to win that one on our own.
You do gain from it too, because... well, think of it this way: Annoying replies of naggers (like mine right here) would vanish, and best of all, your well intended help & advices would become much more beneficial and thus worth your efforts.

You can't, it's fixed. And they've even neglected to normalise some of the a/b part types of count-ins at that, so those actually sound louder than the rest of the drums.
As a beta tester I started complaining to them about this at least 3 years ago, so far it's been completely ignored.

Hi, I have version 2022 for Windows, and I disabled count-in, but it plays regardless when the song loops over. I have it set on looping the entire song.

Thanks!