The type or namespace name 'MIDI' does not exist in the namespace

I have 开发者_开发知识库a midi.dll, where do I install the file with Monodevelop IDE?

If it is a .NET dll you need to add a reference, look at the Referencing our library part of the documentation to see with screen shots an all how to add the reference. You should find it on the ".NET Assembly" tab.