It's a problem with the social group system. It just isn't integrated into the TA site well. When you join one, it should automatically be added to the main forum listing for members; TA is using some, dare I say, legacy forum software, and the ability to create groups seems somewhat thrown together. Of course, group members could take the idea and create a little site just for our particular interests using free hosting and software...in the 90's, it seemed as if even the most esoteric of interests had a web ring and forums. Big Search (i.e. Google) kinda killed those close knit groups as they eventually plummeted down the search rankings. :sniff:
Since the social groups don't throw alerts or anything to notify you that there are new posts there, I often forget about them. I'll try to check this one semi-regularly though.
Of course, There are some great site dedicated to electronic music creation; there are good sites dedicated to ios music apps and solutions...but finding a forum dedicated to the palatform is rather difficult. Usually you have to wade through posts on sites that cover everything from pro DJ rigs to PC/MAC recording studio software and everything in between.
The songs need to be on at least one playlist in your idevice. If you click the "more" button in the upper right corner, and then the "manage tracks" tab, there is an explanation there. Just create a playlist with your entire collection.