Very often I dream I am able to fly due to an enormous concentration of the mind. This is a sensation I am unable to describe verbally. Also, I frequently hear music while I am dreaming: from familiar melodies to unknown sounds and harmonies. Spirits is the title I gave to a music I heard many times, but most intensively in August 1990, when I was living in a cottage at Elstree, Hertfordshire. This experience was so strong that I felt impelled to write down the music immediately. What struck me mostly was that, in my dreams, every time I heard this music I found myself suspended in the air. The sounds resembled human voices singing very short motives recurring over a very long - and almost everlasting - time span.