The same thing happens in music.

Lefebure-Wely was a wonderful improviser (I can say this emphatically, for I heard him) but he left only a few unimportant compositions for the organ.

I might also name some of my contemporaries who express themselves completely only through their improvisations.

The organ is thought-provoking.

As one touches the organ, the imagination is awakened, and the unforeseen rises from the depths of the unconscious.