Passive listening doesn’t help, you say? Well, how are you supposed to play a song you’ve never heard?
How are you supposed to do a Lady Gaga impression when you’ve never even heard her speak or sing?
I’ll tell you how…you make it up. You get creative. You invent something new.
And therein lies the problem.
Japanese doesn’t want your creativity. Japanese doesn’t want your inventiveness. Because the second you, an adult foreigner with a 20-word active vocabulary, start “inventing” Japanese, what you have invented ceases to be Japanese. It’s certainly based on Japanese, but it’s not Japanese.
Don’t create Japanese.
Imitate. Imitate. Imitate.
Be creative in your methods. Go wild. But know that the aim is to do a perfect, note for note impression of a Japanese person. Be creative at being a copycat. That is the point of learning Japanese as far as you will be concerned for the foreseeable future.
There will come a time to put your own little spin on it, to add your unique flava, but that will be the 0.0000001% on top of 99.999999% Japaneseness. Fake numbers, of course. But I hope you get the point.