I'm on a Mac. I just had a heck of a time trying to install 2020 with Xtra Styles PAK 8 from the external drive that was sent to me on to my computer, as recommended. The video is fast, doesn't match what I see, and in the end I thought I was done but underneath everything I found the Installer saying a minute left, frozen.
During what I thought was the installation, I rebuilt the Styles and the total number was listed as 6210 but I could not find the names of the styles on the PAK 8 demo video.
So, how do I install them from the external drive to my internal, so they'll be with the rest of the program?
Also, while the Installer was frozen, in the Log it said there were errors. It would not let me close out of it nor the Mail app so I just pulled the plug after an hour.

Are you talking about the Band-in-a-Box Setup.pkg which is on the hard drive? When you launch that you can tell it to copy everything to your internal Mac hard drive from the USB hard drive, which is presumably what you did. It runs a script to do this, and if you currently don't have ANY of the UltraPAK files on your Mac drive, then it will take a long time, perhaps 30-60 minutes. The installer app GUI sometimes says 1 minute left, which is bad I agree, but Apple has not provided any way that I am aware of to modify that text; it just says 1 minute left while it's running scripts.

If you force quit the installer before the script finished which is what it sounds like you did, that's fine. You can run it again, select the same option, and it will pick up where it left off. It only needs to copy and update files as needed.

The drive doesn't ship with the Xtra styles installed. Xtra Styles PAK 8 is a separate 150 MB installer package, and if you purchased it, it will be available for download from your online account - are you sure you got it? That installation is quick (under a minute), and you can choose to install it either on your Internal drive, or choose any volume (like the Band-in-a-Box hard drive) at the 'choose destination' screen.

Thank you, Andrew. Silly Apple, ok, I won't take the time literally.

I threw everything into the trash, did it again, left the room for several hours, came back and it looked complete and the Installer didn't freeze.

So, there are 6210 styles total? I listened to an interview on a FB group with the person who is the voice of the videos. I thought he said a number that was a 7,000.

Now I need an up-to-date tutorial. I know there are a lot but some go back to when it all looked DOS-y.

For example, now the program is dark and gray. I know Mac, when it is night outside and hard to see, likes to have a dark mode so it is dark and hard to see on the screen also, but I would rather see. I went to Help and it only pointed me toward the Mac itself in its dark mode. The chord sheet is dark and the chords are a dark gray. I think some designer is laughing their head off at me right now. It is not polite to laugh at old people.

I don't have the Mac version, but some of these settings are now user definable.

Try pressing Command-T to see if that toggles the screen display, and also right-click on the chord sheet and see if you have a Display Options menu item available, which allows you to change certain colors, font styles etc:

The total number of styles available at the current time can be seen in the StylePicker if you select show all styles including N/A ("Other" drop-down). The number just above the style list is the total, if there are no other filters active. First, make sure to Rebuild if you have not done so. You won't have all available styles, but that allows you to see the grand total of styles available from PG Music.