I guess what you are asking is how you can create a play list, potentially shared by multiple devices. If that is the case, you have a couple of choices:
keep the playlist in the receiver: this is the simplest option. This will be a simple array on the receiver, kept in memory, which will go away when application ends. A custom receiver is required and it can implement the methods such as "append, insert, get, clear, ... to provide what the senders need. When each sender connects, it can ask (calling 'get' for example) for the current "queue" and then can modify the queue by other methods such as 'clear', 'append', 'insert', .... Note that there is no long-term persistence on the receiver (local storage is available but will be cleared as son as the app is gone).
- keep the playlist in the cloud: you need to do most of the things that you do in the previous option but you also persist the playlist to the cloud; the advantage is that playlist lasts beyond the life of a session (this may or may not be desired). In addition, sender apps can potentially get the playlist fro the cloud directly, if needed.
The important thing is that the main storage for your playlist is not your sender devices; they don't know (and shouldn't know) abut the presence of other senders in the eco-system.
On the receiver side, we recently published a simple sample that sows how the notion of (local) playlist can be implemented; that is a simplified example but is enough to show that with minimal work, you can take advantage of the Media Channel; for more sophisticated handling of a shared queue, you definitely need an out-of-bound channel/namespace to handle all the additional api's that I mentioned above.
