I had to take a year of Music History in college to get my music minor, (man, has that come in handy! and I remember a little from the course. So if this is wrong, don’t blame me – blame my Music History teacher.
The Mannhiem orchestra at some point had a very loyal, active local following. It was kinda like following a local sports team today. The orchestra would come up with certain signature orchestrations that the fans became used to and would look forward to hearing. I imagine they’d probably get excited when they heard one coming. It’s like when your team scores.
The “Mannheim Steamroller” was executed by having different instruments come in one after the other and keep building and building to a loud wall of sound.
The “Mannheim Rocket” was executed by instruments forcefully going from low notes to high notes, I think all at the same time.
There were a few more, too, but I can’t remember.
I always thought that the group “Mannheim Steamroller” just picked that name referring to the Mannheim orchestra because it’s witty. Are they really from Mannheim?