Not Quite. It's a little more devious than that.
What they doo is release the origional Beatmania as a 'key disc'. There is an option on the main menu that says "Disc swap". When you select that function, it prompts you (In japanese) to "Please, oh honorable person, remove this mix and put in another mix, or else I will be forced to kill you very swiftly with my sword."
This is where the append discs come in. Append discs are discs you buy seporately and are the ones you swap out your key disc for. Once you swap, the game loads and the new mix is started.
Yeah, it's devious. However, there are a few redeeming factors about this idea. Beatmania and a controller sometimes comes in bundles. Can you imagine the nightmare if they had to bundle a controller with every different mix? (For the record, I think there are about 9 or 10) And also, the other key disc, Beatmania 6th mix+Core Remix is actually two games in one, and doesn't suck donkey nuts like the origional Beatmania did.
To sum up, you boot with one of these three discs:
* Beatmania (Actually Beatmania 2nd mix, but they just call it Beatmania)
* Beatmania 6th Mix+Core Remix
* Beatmania : The Sounds of Tokyo
Then you go to a menu selection and then can swap the disc out for an append disc:
* Beatmania Yeatsu Mix (They include this one with the origional Beatmania)
* Beatmania 3rd Mix
* Beatmania 4th Mix
* Beatmania 5th Mix
* Beatmania Gotta Mix
* Beatmania Gotta Mix 2
You get the picture.
Except with my current setup (Boot CD and a spring), when I attempt to swap discs, it doesn't recognize it. I think it might be because of the region, because if I boot the append discs by themselves, they dont error out on me, they give me the error message ("Cheapskate! Go buy a key disc or else we will run you through with a sword. BONZAI!!!"😉
Is this clearer?