Mine was a wild specimen which I bought from a local shop. It took a long time to get it to sing.
Being an insectivorous bird, I eventually fed it with Jeffrey Low's dry food. And some crickets as supplements in the evening.
Lately, it has tame down somewhat and I was able to take a short video of it from a distance of 3 meters away. Still not in full form yet. I am hoping its song would improve over time :)