Automated downloads from internet to folder on computer

I would like a way for my music playlist or any other playlist that I select on youtube to be synced with my "play music" app on my phone as a playlist. I've looked around on the internet for awhile I it seems like nothing of that nature exists. I was wondering if there was anyway a plugin or program could be made to do such a thing. Right now, music goes to my "play music" app through google play music manager on my computer that is synced to a folder (in this case called music) that I manually add music that I download from youtube when I add it to a playlist. I would like that whole system to be automated if possible. (optional: compatible with other websites such as soundcloud, bandcamp etc.)