The importance of music can also be studied in terms of what kind of music a person most liked, perhaps their experiences of concerts and their own musical activities - singing, playing an instrument, choirs and orchestras...
But none of this gets close to understanding what music meant to that person.
This came to my mind recently in relation to Owen Barfield - because classical music was extremely important in his life.
For example, OB told his biographer Simon Blaxland de-Lange that music was even more important for him than language - which is remarkable given that Barfield's reputation mostly rests on his studies and interpretations of language.
In a biographical note, Marjorie Lamp Mead wrote that: "throughout his life, Barfield’s love of music was a strong force. For as much as he desired to be a poet, Barfield viewed music as the essential element in his life – even in preference to poetry."
Barfield's main modern editor, Jane Hipolito, wrote to me that Barfield had a deep love for, and considerable knowledge about, classical music - including most of the great composers and all of the major genres. She also said that when listening to music with Barfield she noticed that he paid total attention to the music with exclusion of all other activities - with an intensity that she has only seen matched by a few professional musicians.
But the solid facts that Barfield experienced music with intensity, and that he himself regarded music as having primary importance in Life - are matters that we find it hard to make use of in understanding the man.
Or, at least we find it impossible to use such information in any systematic biographical way - it is evidence, but evidence that we can weave-into our usual biographical accounts. We somehow cannot use musical appreciation as 'evidence' - and indeed even the word 'appreciation' trivialises what was actually a vital experience.
And this is an indicator of the limits of how we understand other lives by using biographical 'fact's. I am not saying that understanding of another person is impossible - in fact I am sure it is possible; but that this understanding does not and cannot emerge-from an assemblage of facts-about-them.