As the son of two professional musicians and an amateur musician myself, what kind of music, (similar to what kind of exercise) do I consider to be the very best?
Answer: vocal only music, usually in 3 to 5 parts!
The answer is very simple.
Because it is the most pure, elemental, and basic form of music. All musical instruments are just approximations of the human voice; with the ability to amplify it, alter it, and otherwise mess with and to try to enhance the human voice.
Usually, though, the effect is more like when you attend a concert and the volume is up WAY TOO HIGH.... (Sound familiar?) The whole performance is wrecked.
When you hear a good performance of pure acapella vocal music sans musical instrumental accompaniment, you are hearing music in it's purest, most elemental form.
Real music. Ancient music. Music without additives.
Here is a sample I think you'll like from the Isaacs, a family group consisting of the mother, two daughters and son. Pure and simple.
No trans fats. No refined, bleached flour. No sugar.