I’m interested in adding my own music to the tavern - specifically I am running a Dragon Age campaign and want to add music from the computer game soundtrack. How would I do that?
You would have to be a Supersyrin subscriber and upload the sounds (in this case the music) with help of the Soundset Creator as an own soundset. This would of course only be for personal use.
Yep with the Syrinscape Soundset Creator (which comes as one of the many benefits of the Supersyrin sub) you can add your own music and sounds, copy and edit existing soundsets or create your own and then sync your creations across any of your devices.
The Creator is the same tool that we use to build soundsets so it’s a really powerful tool and lots of fun 
I have subscribed to the Syrinscape Soundset Creator but am not particularly tech savvie, I’m afraid. Does the music I hope to add need to be in a particular format? I have some MP3 and some WAV files - do they need to be converted into some other format first? If so, how does one do it?
Many thanks.
The format of your choice should be the WAV format. Convert the music you want to include into your soundset into that file format (be aware that it must be 44.1kHz, 16bit stereo!!!), software like Audacity helps greatly with that.
After you installed the creator you may want to install the soundset you want to enhance in the creator. Once it is installed, go to (by clicking on it in the left column), shortly after that, the column changes to all the included moods (the same as you click on in the players). The middle window shows all the elements - this is the place where your music will be. Create a new element (called DragonAge music) and put the music in here.
There are Youtube tutorials on importing samples and on which settings to adjust, it would be too much and be described properly here - give them a try, they are easy to follow and simply superb! 
I’d like to do this too for a modern setting game, and I have a copyright question: if I own the sweet classic rock sound track that fits the scene perfectly, can I upload to the Creator and use for personal use via the player?
If it’s only for personal use then yes you can. It’s just like when you copy a CD to your iTunes library. It’s on our server but only you can access it