Anvil Studio

Track view of Anvil Studio.

Anvil Studio is a free MIDI editor developed and published by Willow Software. It has been around for many years and still sees regular updates. It is a full-featured MIDI editor giving you the ability to create complex MIDI files and view songs in various ways. I used to use Anvil Studio all the time, however, it's constrictive interface, has led me to prefer LMMS instead.