     ///   - portID:     MIDI Unique Port ID
     ///   - offset:     the offset in samples that this event occurs in the buffer
     ///
-    public func receivedMIDIController(_ controller: MIDIByte,
+    open func receivedMIDIController(_ controller: MIDIByte,
                                        value: MIDIByte, channel: MIDIChannel,
                                        portID: MIDIUniqueID?,
                                        offset: MIDITimeStamp) {

    ///   - portID:     MIDI Unique Port ID
    ///   - offset:     the offset in samples that this event occurs in the buffer
    ///
    public func receivedMIDIAftertouch(noteNumber: MIDINoteNumber,
                                       pressure: MIDIByte,
                                       channel: MIDIChannel,
                                       portID: MIDIUniqueID?,

    ///   - portID:          MIDI Unique Port ID
    ///   - offset:          the offset in samples that this event occurs in the buffer
    ///
    open func receivedMIDIPitchWheel(_ pitchWheelValue: MIDIWord,
                                       channel: MIDIChannel,
                                       portID: MIDIUniqueID?,
                                       offset: MIDITimeStamp) {
