 
         frequencyParameter = tree.valueForKey("frequency") as? AUParameter
         amplitudeParameter = tree.valueForKey("amplitude") as? AUParameter
+        detuningParameter  = tree.valueForKey("detuning")  as? AUParameter
 
         token = tree.tokenByAddingParameterObserver {
             address, value in

///
/// - parameter frequency: Frequency in cycles per second
/// - parameter amplitude: Output Amplitude.
///
public class AKOscillator: AKVoice {


    ///
    /// - parameter frequency: Frequency in cycles per second
    /// - parameter amplitude: Output Amplitude.
    /// - parameter detuning: Frequency offset in Hz, Default: 0
    ///
    public init(
        waveform: AKTable = AKTable(.Sine),
        frequency: Double = 440,
        amplitude: Double = 1,
        detuning: Double = 0) {


        self.waveform = waveform
        self.frequency = frequency
        self.amplitude = amplitude
        self.detuning = detuning

        var description = AudioComponentDescription()
        description.componentType         = kAudioUnitType_Generator
