Psycle is a professional program to create music, properly a VST host that uses a tracker interface. The program is bundled with over 35 virtual instruments and effects, and supports the addition of external VST plugins. It is open source, quite lightweight for all the features it offers, and easy to install and configure.
Using Psycle is quite straightforward since it works in a very intuitive way: instruments and effects, also called ‘machines’, are represented by blue and green boxes respectively. Once in the main window, these boxes are connected through arrows to the ‘master’ box which is actually the sound output. In this way, you can add and connect instruments and effects according to your needs, specifying their parameters, and making the necessary adjustments. Notes can be inserted with the keyboard or with a MIDI-enabled device. After this, you can edit your music using the ‘pattern editor’ that supports up to 64 tracks. The song or sequence will be saved as a .PSY file by default, however you can also save it as .WAV, which will allow you to convert it into other formats afterwards.
The program comes with comprehensive help files and tutorials, complemented by online documentation. Also, from the website you can download VST plugin packs, instruments, general purpose plugins, for example themes and skins, and even share your works or interests with the online community.