I hope its more than 20 tracks because that is no where near enough. Anyway I doubt its just 20 tracks because how could you get 70 variations out of 20? That would mean 3(3.5 technically) variations per track if it were spaced out evenly. Some tracks don't have that many. Some only have 1. So some tracks will end up having 4 or 5 variations. Or maybe more. How many tracks have that many variations? This is why I think there will be more than 20. Not only because that is absurdly low amount.