Basic use
To compose a song with Sointu, you first need to make your instruments using the instrument editor.
Then, if you run Sointu as a VSTI plugin, you can compose the song in your VSTI host, and once done, hit "Record", play the song from the VSTI host side. Once it is done, hit Record again to stop recording. Sointu will reconstruct order list and patterns from the MIDI events received between starting and stopping recording.
Alternatively, you can compose the song entirely using the integrated tracker in Sointu. In this case, in the order list, you define what patterns appear in which order in the song, and then use the pattern editor to edit the contents of these patterns.
Here's a quick overview of the user interface.
The default key bindings are documented in keybindings.yml.
Full list of possible actions that you can bind keys to can be seen in the keybindings.go.
You can configure your own key bindings by making your own keybindings.yml in the Sointu configuration directory i.e. os.UserConfigDir()/sointu/keybindings.yml. On Windows, that location is AppData/Roaming/sointu/keybindings.yml. See here how to find os.UserConfigDir() on other platforms.
The user-defined key bindings define the changes from the default key bindings, and a line with no action unbinds the key. For example, - {key: "A"} unbinds the A-key from its default behavior (making a NoteOff row) and - {key: "A", action: "PanicToggle"} would override the default behavior, to make A-key toggle panic.