             updateTuningTable()
         }
     }
-    // -2, -1, 0, 1, 2, etc.
+    
+    // Musically useful for instrument register
+    // ..., -2, -1, 0, 1, 2, ...
     public var octaveAtMiddleC: Int = 0  {
         didSet {
             updateTuningTable()

        tuningTable(fromNumberField: nf)
    }

    public func tuningTable(fromNumberField inputNumberField: [Element]) {
        if inputNumberField.count==0 {return}
        
        // octave reduce
        let nfOctaveReduce = inputNumberField.map({(number: Element)->Element in

            if lineStr.hasPrefix("!") {
                if !parsedFirstCommentLine {
                    parsedFirstCommentLine = true
                    #if false
                        // currently not using the scala file name embedded in the file
                        let components = lineStr.components(separatedBy: "!")
                        if (components.count > 1) {
                            proposedScalaFilename = components[1]
                        }
                    #endif
                }
                continue
            }
            
            if !parsedFirstNonCommentLine {
                parsedFirstNonCommentLine = true
                #if false
                    // currently not using the scala short description embedded in the file
                    scalaShortDescription = lineStr
                #endif
                continue
            }
            
