Portable SimpleComposer

When it comes to expressing yourself through music, the Internet is filled with all sort of applications that could help you do just that, regardless if you're a professional or amateur composer.
One of them is Portable SimpleComposer. It's a free and simple software solution to writing, editing and playing all sort of MIDI files on your computer.

Sleek and simple graphical interface

The application sports a really intuitive and straightforward graphical interface that provides you with all the tools that you need at your fingertips.
It doesn't come with any customization options, but you wouldn't really need them since the interface is quite intuitive and with plenty of nice tools at hand. It also has some tips and instructions on how to get started and create MIDI files.

Create MIDI files easily.

You will need a MIDI keyboard in order to use this application, but if you lack one you can open and play MIDI files. When you play a tune, only quarter notes will initially be shown on the staffs. In order to edit notes, you will need to use the arrow keys to move the highlight.
It lets you change notes by pressing keys on the keyboard and you can insert a quarter rest if you want. You can also preview your MIDI notes and it lets you edit music written in this program.

Additional features and tools

You can use transpose up and down tools, and it comes with the option to use multiple key signatures. It also lets you adjust the volume and it comes with the option to adjust tempo and it lets you link or un-link keyboards. When you're done creating the MIDI file, simply save it on your computer.
All in all, Portable SimpleComposer is a small but very useful application for creating and playing various MIDI files on your computer.