You may not like this piece...

...and yet, I think it's worth listening and learning to play. This is Estampie Retrove from the Robertsbridge Codex - the oldest surviving organ piece in the world. It only has two voices and is considered a Medieval dance. It was created about 700 years ago in the 14th century (ca. 1360).

This was the time when Bocaccio wrote his Decameron, when Europe suffered from the plague, and when in churches the Blockwerk organ (with large mixture sounds up to 24 ranks but without the ability to change the stops) ruled.

But since this is a dance, it was probably not mean to perform in churches. Instead this type of music sounded best in courts performed on positive and portative organs (the ones that you see Saint Cecilia and the angels play in early Renaissance paintings).

To our modern ears the sounds of Estampie would sound rather alien because of open fifths. This was of course the time when the instruments were tuned in pure perfect fifths which was called the Pythagorean temperament (a little similar to how stringed instruments are tuned today). 

I would not be surprised if you don't like this piece at all, since there are no sweet-sounding intervals, like thirds and sixths here. And no major and minor chords, for that matter. Just empty and calm open paralel fifths and octaves.

Very strange music. Not a favorite style and mostly unknown to many organists, But indispensible and fascinating to learn to a few who care deeply about the origins of our beloved instrument.