I know it would increase capital a little, but would it be possible to create a small recording studio inside of the place? That way, instead of just practicing, musicians could record. Producers and sound people would have a place to come too. Also, it could be a stepping up point for CD and MP3 sales.

What about identifying artists who would be willing to teach classes. Maybe in return for free coffee or something. Successful artists by themselves attract groups of people. Then, the people that come for the classes would buy coffee too and would be more likely to become return customers because of the great experience that they had.

Have you ever been to a coffee house with a karaoke machine? I haven't. Would you go to one?

And since you have all of this sound equipment, maybe some budding producer would be willing to teach a few classes for connections to a few Albums to produce.

Good Luck.