I would like to select multiple songs for the music app to play. The files are presented as tiles. Is there any sort of multi-select, other than brute force click'm all?
You can select multiple tiles by using the right mouse button:
This works not only in Music, but in many other applications, e.g. in SkyDrive. Also, you can replace right-click with Ctrl-left-click, so to select songs this way you would: