If you become a more active member and begin to post X amount of posts per a day, then you should be able to reach 3 posts per day fairly easily. That way you don't have to post another 303 posts in order to claim a song. Just try to post at least, I'd say, 10 or more posts a day and it should go up in no time. You can find that in your statistics tab if you didn't know.
It won't be very long. Especially if you post without noticing your post count. It'll go up more quickly than you think if you do just that. It's kind of like how time seems to go by faster if you're not paying attention to the clock, you know?