I have been asked to build one for the local symphony.A search has revealed they range from simple boxes to elaborate affairs withinternal sounding boards coupled to the top. The problem with in Internetsearch is that one finds what has or can be done with little hint as to what isacceptable or common. Specifications from the music director has conflictedsome information from manufacturers of these things. For example, directorthinks a hard top is required while a company that makes a particularly sophisticatedone specifies fir plywood