Bosca Ceoil - A free, easy to use tool for creating music.
Jokosher - Jokosher is a simple and powerful multi-track studio.
Renoise - Renoise is a digital audio workstation.
Fission - Edit audio in minutes, not hours.
Zynewave Podium - Podium is a modern digital audio workstation (DAW) for Windows.
Audacity - Audacity is a free and open-source audio production software suite that includes a surprising array of editing tools and recording systems.