Musagi is a fairly sophisticated music editor and synthesizer which is more polished than most shareware or commercial products available in the market. The program comes with a broad range of instruments, from predefined retro sounds that can be customized to a MIDI interface and a WAV sampler.
Even if you're not a composer and do not hook up your musical instrument to record tunes on your PC or use the keyboard to play them, you can ignore the more advanced sound-editing features and start composing a nice melody right away.
Be sure to read the text file in the documentation folder, then check out the nicely written step-by-step tutorial that will guide you in composing your very first tune. - Lim-Dul