This is the last chance to make a change to the way something sounds, and catch any mistakes that were missed during the mixing stage. Decisions made at this stage are what appear on all copies and duplications of a song. Finishing touches are applied via EQ, compression, limiting, stereo enhancement, exciters, noise reduction, etc., in order to give the song a final “polish”. The song volume will also be increased in order to compete with other commercial songs in the same genre. If multiple songs are involved (an album or EP), the songs will be placed in a logical and/or desired order. Fade ins and fade outs are addressed as well.  My primary goal as mastering engineer is to provide a high fidelity, high clarity, professional product that translates over a wide range of playback systems.