CoreMIDI is an API that talks to the MIDI server on iOS and OSX which in turn interacts with MIDI devices connected to your Mac or iOS device.

When using CoreMIDI, you will run into various classes that deal with different parts of the MIDI stack, the following graphic illustrates the relationships:

The MIDI device itself is represented by the MonoTouch.CoreMidi.MidiDevice class. Devices can contain one or more entities (MonoTouch.CoreMidi.MidiEntity). For example a MIDI device could contain two independent MIDI tone generators. Each Entity contains a series of endpoints which are either sources or destintions. Both MIDI sources and MIDI destinations are encapsulated by the MonoTouch.CoreMidi.MidiEntity class.

To start with MIDI, you will need to create a MonoTouch.CoreMidi.MidiClient object. This object is the gateway between your application and the MIDI server process. You subscribe to the events that this object raises to track devices being added, removed and to changes in their properties and setup configuration.

You also use the to create input ports and output ports. The input ports raise the event when new MIDI data is available and you can use the MonoTouch.CoreMidi.MidiPacketsEventArgs.Packets property in the arguments received to get the data out

See the class for an example of how to set things up.

To use networked MIDI connections, you need to enable the network session and set its connection policy, like this:

var session = MidiNetworkSession.DefaultSession;
session.Enabled = true;
session.ConnectionPolicy = MidiNetworkConnectionPolicy.Anyone;
	

To connect to a remote MIDI network host you use the , like this:

var host = MidiNetworkHost.Create ("My Session", "myhost.xamarin.com", 5004);
var connection = MidiNetworkConnection.FromHost (host);