Who said "The gratitude of the heart is the truest music."?

This quote is attributed to Jack London.

The gratitude of the heart is the truest music. - Jack London

"The gratitude of the heart is the truest music."

Jack London Gratitude

Novelist American 1876–1916

"The proper function of man is to live, not to exist."

"I would rather be ashes than dust."

"You can't wait for inspiration. You have to go after it with a club."

"The wise man doesn't give the right answers, he possesses the right questions."

"Gratitude makes life richer."

"A grateful heart is a happy heart."

"Respect those who came before us."

"Life's greatest treasures are the people we love"