Music is a great motivator. A fast paced loud song can pump you up in any situation. This makes music a very good partner in the gym. Some songs just pump you up with a fast tempo and heavy guitar riffs while other songs can inspire you to go that extra mile with motivating lyrics. For some reason hip hop and metal works best when it comes to workout songs. The rhythm of these songs also helps you match your workout to the rhythm and makes it easier to do more reps than you are used to.