Group Piano Lesson Method Book for middle school music clas

A school music teacher is interested in a good method book from which to teach class piano during a 6-8 week time period during the school year. Any advice?

Although I'm not fond of the Alfred method, they have a group piano course leveled 1-4.

http://www.primamusic.com/InstrSearchRes...A1-386B6000E242

Any modern piano course can be used in a group setting.

I recently was searching for a group piano method, and this was pretty much all I could find for children. There are adult ones intended to be used at college level beginner piano class, but I don't think those would be good for middle school kids.

I would use this method plus a LOT of supplemental material.