Best way to play MIDI sounds using C#

I'm working on a C# MIDI application at the moment, and the others are right - you need to use p/invoke for this. I'm rolling my own as that seemed more appropriate for the application (I only need a small subset of MIDI functionality), but for your purposes the C# MIDI Toolkit might be a better fit. It is at least the best .NET MIDI library I found, and I searched extensively before starting the project.

I think you'll need to p/invoke out to the windows api to be able to play midi files from .net.

This codeproject article does a good job on explaining how to do this: vb.net article to play midi files

To rewrite this is c# you'd need the following import statement for mciSendString:

[DllImport("winmm.dll")] 
static extern Int32 mciSendString(String command, StringBuilder buffer, 
                                  Int32 bufferSize, IntPtr hwndCallback);

Hope this helps - good luck!

midi-dot-net got me up and running in minutes - lightweight and right-sized for my home project. It's also available on GitHub. (Not to be confused with the previously mentioned MIDI.NET, which also looks promising, I just never got around to it.)

Of course NAudio (also mentioned above) has tons of capability, but like the original poster I just wanted to play some notes and quickly read and understand the source code.