I have taken a look at doubletwist a while ago, and decided it wasn't worth adding to this article back then (I think that was about a half a year ago). I'd have to check it out again, but I think it was because the free version didn't really offer anything that stood out among all the different music players.

My apologies for the late reply. The problem is that in the world of organizing music, there are two ways of doing it. There is the one way, in which you did it - which is to sort everything into folders. Then, there is the more common way - by way of tags. Tags are small bits of information hooked onto your music files which indicate which album they belong to, what the artist is, and what the song's name is. To see what I'm talking about, stick the SD card into your computer and look at your music with Windows Explorer. Go to a track, right-click it, choose "Properties", and then go into the "Details" tab. Here you'll see different fields, such as Title, Rating, Comments, Album artist, Album, Year, etc. These are the song's tags. If the file isn't open in another program, you can also edit most of them. Google play music (and most other music players) organize music based on their tags. If an album is being split into two, look at one track of each of the two "new" albums, and you'll notice the album tag is different. It could be a small difference, or it could be a big difference. Whatever it is, the fact that it /is/ different means that Google Play Music will see it as two different albums. As to your songs ending up in different artist - this most likely comes from you having albums with multiple artists. In Google Play Music (I'll just abbreviate it GPM from now on), if you go into the artists section, different tracks from that album will be under different artists. However, if you go into the albums section, it should all go into the same album. So, basically, GPM uses the tags to sort your music, while Windows Explorer just looks at which folder they're in, and displays your music like that. If you want everything properly organized, you pretty much have two options. The first option is that you get a music player that supports folder-based playback. Rocket Player supports folder-based music playback, so if you like, you can check that out. Just make sure you go into the "Folders" tab, otherwise you'll have your music organized the same way it is on Google Play. If you want a quick solution, this is the way to go. If you want to keep using GPM but have everything organized, you can edit the tags. This can be time-consuming, depending on how much music you have and how many tracks need editing. On the other hand, it has several advantages. For one, you have more flexibility when it comes to sorting your music. You can instantly look at your music sorted in different ways. For example, you can play a mix of music from a certain artist, regardless of which album(s) the music comes from. Or, you can play a mix of music from a certain genre, regardless of artist or album. The other advantage is that you don't necessarily need to organize your music into folders any more - whenever you get new music, you can just dump it into one folder, if you don't mind the mess - it will all appear properly organized in GPM. If you want to edit the tags, you can either do it on your computer or on your device (although that could well not work if you're on Android 4.4). If you want to do it on your computer, you can do it as I explained earlier. If you want to do it on your device, you can do it with Rocket Player - that has the capability of editing tags.

I've just taken a look at the play store listing. It seems to have some interesting features, but it locks the folder-based browsing, tag editing and some other features are locked after 10 days of use unless you buy a key to unlock them.