I would suggest in addition to folders with weight, another option
It would be scripted by folders without weight. The Centova choose a music folder that is in the script; after the last folder back to the first. Ex:

Folder 70´s - Love songs
Folder 80´s - Love songs
Folder 90´s - Rock songs
Folder 70´s - Disco Songs

Folder 80´s - Pop songs
Folder 70´s - Rock songs
Folder 90´s - Rock songs
Folder 80´s - Love songs

Folder 90´s - Dance songs
Folder 80´s - Rock songs
Folder 70´s - Love songs
Folder 90´s - Pop songs

After the last folder back to the first.