Audacity can handle up to 16 channels at once (with the right hardware) and dubs over specific tracks to create multitrack recordings. Basic editing is straightforward, and the usability extends to advanced features, which range from a drawing tool to alter individual sample points to the envelope tool for smoothly fading volume up or down. If you want to do more, Audacity's effects let you change pitch, remove background noises, and alter frequencies with an equalizer -- which is aided by a spectrogram mode for visualizing frequencies. FULL REPORT ...