Okay, you probably already know my experience with the MISSINGNO trick, now check this out...
Note--this is a repeatable glitch, meaning I can do it over and over
Okay, trainer name--"Cloud". I mess up the hall of fame with the MISSINGNO glitch. Then, I head to the hall of fame site...here's what I see.
A glitched-name Machoke
A glitched-name Blastoise
A glitched-name Cloyster
Here's where the fun starts. As soon as I move on to the next one, a Gengar with name MISSINGNO, the music changes to one of two themes (the ones that play on the "Route"s) and goes half-speed. I know it's half-speed, cause I tried this on stadium, and in Doduo mode the music was normal speed. Then follows a glitched-name Mew, a glitched-name Nidoran (which is part ghost type) and that's the end of the site.
The music will continue, however, until I do something else (i.e. talk to Joy, leave Center, Cable Club, etc.). Any speculation on why this might happen?