I'm using SharePoint to host music tracks, which I play with Windows Media Player (WMP).
The player is controlled via WMPLib - Microsoft's WMP API.
I found that I can add SharePoint music files to a WMP playlist via the API, and that the tracks are played. However, when I wanted to display information about the current track (track name, artist, duration, etc), I found that the artist property was empty.
I discovered the fix for this was to URL encode the URL of the track (as it exists in SharePoint) before adding it to the playlist. This was because the track URLs contained spaces (and potentially other odd characters).