Here are some quotes I found on the Internet where many philosophers and musicians explain in simple statements what music is to them:
After silence, that which comes nearest to expressing the inexpressible is music.
Aldous Huxley
All music is beautiful.
Billy Strayhorn
Any good music must be an innovation.
Les Baxter
I don't care much about music. What I like is sounds.
Dizzy Gillespie
If a composer could say what he had to say in words he would not bother trying to say it in music.
Gustav Mahler
If music be the food of love, play on.
William Shakespeare
In music the passions enjoy themselves.
Friedrich Nietzsche
It is cruel, you know, that music should be so beautiful. It has the beauty of loneliness of pain: of strength and freedom. The beauty of disappointment and never-satisfied love. The cruel beauty of nature and everlasting beauty of monotony.
Benjamin Britten
Music expresses that which cannot be said and on which it is impossible to be silent.
Victor Hugo
Music happens to be an art form that transcends language.
Herbie Hancock
Music hath charms to soothe a savage beast, to soften rocks, or bend a knotted oak.
William Congreve
Music in the soul can be heard by the universe.
Lao Tzu
Music is a higher revelation than all wisdom and philosophy.
Ludwig van Beethoven
Music is a moral law. It gives soul to the universe, wings to the mind, flight to the imagination, and charm and gaiety to life and to everything.
Plato
Music is a performance and needs the audience.
Michael Tippett
Music is love in search of a word.
Sidney Lanier
Music is moonlight in the gloomy night of life.
Jean Paul
Music is my religion.
Jimi Hendrix
Music is the best means we have of digesting time.
W. H. Auden
Music is the movement of sound to reach the soul for the education of its virtue.
Plato
Music is the shorthand of emotion.
Leo Tolstoy
Music is the soul of language.
Max Heindel
Music is well said to be the speech of angels.
Thomas Carlyle
Music should be your escape.
Missy Elliot
Music was my refuge. I could crawl into the space between the notes and curl my back to loneliness.
Maya Angelou
Music washes away from the soul the dust of everyday life.
Berthold Auerbach
Music, in performance, is a type of sculpture. The air in the performance is sculpted into something.
Frank Zappa
No good opera plot can be sensible, for people do not sing when they are feeling sensible.
W. H. Auden
One good thing about music, when it hits you, you feel no pain.
Bob Marley
When words leave off, music begins.
Heinrich Heine
Writing about music is like dancing about architecture.
Laurie Anderson
You are the music while the music lasts.
T. S. Eliot
…And they all have their own definitions…