The way the Orchestrion is set up unfortunately makes such an idea impossible, as it would require specific music to be coded to run within it (it's not a regular music player) - tracks it uses are specifically coded for it and utilize the secondary sound channel the game client normally uses for battle music and certain sound effects (this is why it's locked to housing, battle music naturally is not needed to be cued up inside a house).

Also there is the small problem of copyright licensing SE would have to do with Spotify just to use their service, on top of licensing with the various music labels that provide music to it, a very expensive and time-consuming effort with little benefit. This would be just not possible I'm sorry to say.