There are a plethora of recordings of as many different organists that have recorded this great JS Bach work. Each one has their own interpretation of the music and may sound quite different.
It is a major organ solo work which requires great dexterity at the organ console for the hands as well as the feet. Probably one of JS Bach's most famous (and often performed too often in concerts)...
It generally includes a toccata, kind of like a prelude, and a fugue, where four voices in this case literally compete against each other since counterpoint means "notes against notes".
For much the same reasons as the rest of Johann Sebastian Bach's compositions were: to earn a living, basically, and give the rest of the world the opportunity to enjoy all of his compositions.It's...