[ ] If we work on a subset and run the drum extraction of the midi files we will also overwrite the already fully one with the subset one - one of the examples why the state management in jupyter is horrible because its all over the place, spammed with global variables. The problem is that caching on a subset is even more difficult because the subset must be fixed in order that the caching works as expected. Maybe instead of storing the stuff in memory we should write a metadata file but this is also not so nice... mh
As proposed in https://github.com/capital-G/musikinformatik-sose2021/issues/24#issuecomment-821833676