Ok, I am familiar with this situation, as we just went through this with a local band I manage here... HOWEVER, "here" the houses aren't so close together...

Our town has a noise ordinace. You most likely do too. Perhaps the "Band" is unaware of that.

You talked to the parents and that's a good start. My next suggestion BEFORE you call the police is to try and talk to the "Band" personally. Maybe get a few others in the neighborhood together and have a meeting with the "Band". Wether you like their music (noise ) or not let them know that you are all for them practicing and hope they maybe go somewhere in their career but, you and others have a right to peace and quiet at reasonable hours.

My reasoning for you to talk to the "Band" is this: More than likely they are teenagers, when "Turn it down or Turn it Off" comes from the parents they'll blow it off or turn it up... After all, "Parents Just Don't Understand" ...But if they are serious about being a "Band" then they most likely will respond to your request.

If that doesn't work... Then call the Boys in Blue.

But I strongly recommend you try talking to the "Band", not just the parents.

Wishing you some peace & quiet...

Katie