Spectro - Spectro is a freeware audio file analyzer 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.
Lossless Audio Checker - A utility to check whether an audio file is truly lossless or not.
TwistedWave - TwistedWave is one of the unique audio editors that allow you to edit your music file online without any installation.
sndpeek - a real-time audio visualization tool (animated, 3D)
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.