LMMS - Make music with a free, cross-platform tool
Reaper - Reaper is a focused digital audio workstation (DAW) developed by Cockos. In the creation of the software, the digital audio technology company intended to make audio editing accessible to the masses.
Audio Cleaning Lab - Looking to clean up your song recordings? Download SOUND FORGE Audio Cleaning Lab, the professional solution for cleaning & restoration with advanced ProAudio technology.
Audacity - Audacity is a free and open-source audio production software suite that includes a surprising array of editing tools and recording systems.
DSP-Quattro - DSP-Quattro
FL Studio - Image-Line's FL Studio, now on it's 12th version, is a well-known music production suite and the most popular beat processor on the market, due no doubt to its longevity. Read more about FL Studio.