MIDI Library help

I'm having trouble using the MIDI Library. Specifically the callback functions.

http://arduinomidilib.fortyseveneffects.com/index.html

I downloaded this library and installed it. Im trying to start from the example MIDI_Callbacks. In order to see if the library is working, I'm simply trying to turn the pin 13 LED on and off on my Arduino UNO. A midi note on would turn the LED on and a note off turns it off. The only thing I've added to the example is a digitalWrite(led, HIGH) and a digitalWrite(led, LOW).

I'm using Hairless MIDI to serial bridge. I can see the note on and off is getting to the arduino UNO. the RX light lights up, but nothing ever lights up the pin13 LED.

I assume I'm missing something simple. I'm new to this. The code is below. Any help would be greatly appreciated!
Clark

#include <MIDI.h>

int led = 13;

// This function will be automatically called when a NoteOn is received.
// It must be a void-returning function with the correct parameters,
// see documentation here:
// http://arduinomidilib.sourceforge.net/class_m_i_d_i___class.html

void HandleNoteOn(byte channel, byte pitch, byte velocity)
{
// Do whatever you want when you receive a Note On.
digitalWrite(led, HIGH);

if (velocity == 0)
{
// This acts like a NoteOff.
digitalWrite(led, LOW);
}

// Try to keep your callbacks short (no delays ect)
// otherwise it would slow down the loop() and have a bad impact
// on real-time performance.
}

// -----------------------------------------------------------------------------

void setup()
{
pinMode(led, OUTPUT);
// Initiate MIDI communications, listen to all channels
MIDI.begin(MIDI_CHANNEL_OMNI);

// Connect the HandleNoteOn function to the library,
// so it is called upon reception of a NoteOn.
MIDI.setHandleNoteOn(HandleNoteOn); // Put only the name of the function
}

void loop()
{
// Call MIDI.read the fastest you can for real-time performance.
MIDI.read();

// There is no need to check if there are messages incoming
// if they are bound to a Callback function.
// The attached method will be called automatically
// when the corresponding message has been received.
}