         }
     }
 
-    // From Erv Wilson
+    /// Recurrence Relation 01 Preset From Erv Wilson
     public func presetRecurrenceRelation01() {
         tuningTable(fromFrequencies: [1, 34, 5, 21, 3, 13, 55])
     }
-    // From Erv Wilson
+    
+    /// Highland Bag Pipes Preset From Erv Wilson
     public func presetHighlandBagPipes() {
         tuningTable(fromFrequencies: [32, 36, 39, 171, 48, 52, 57])
     }
-    // From Erv Wilson
+    
+    /// Persian North Indian Mdhubanti Preset From Erv Wilson
     public func presetPersianNorthIndianMadhubanti() {
         tuningTable(fromFrequencies: [1.0,
                                       9.0 / 8.0,

//  Copyright © 2017 AudioKit. All rights reserved.
//

@objc open class AKTuningTable: NSObject {

    public typealias Frequency = Double

    private static let NYQUIST: Frequency = AKSettings.sampleRate / 2

    public static let midiNoteCount = 128

    public var middleCNoteNumber: MIDINoteNumber = 60 {
        didSet {
            updateTuningTable()
        }
    }

    public var middleCFrequency: Frequency = 261.0 {
        didSet {
            updateTuningTable()
        }
    }

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

        return trimmedString
    }

    /// Get frequencies from a Scala string
    open func frequencies(fromScalaString rawStr: String?) -> [Frequency]? {
        guard let inputStr = rawStr else {
            return nil
