Full Idea
Music charms us although its beauty only consists in the harmony of numbers.
Gist of Idea
Music charms, although its beauty is the harmony of numbers
Source
Gottfried Leibniz (Principles of Nature and Grace based on Reason [1714], §17)
Book Reference
Leibniz,Gottfried: 'Philosophical Writings', ed/tr. Parkinson,G.H.R. [Dent 1973], p.203
A Reaction
'Only'! This is a super-pythagorean view of music, as you might expect from a great mathematician. Did he understand the horrible compromises that had just been made to achieve even-tempered tuning? Patterns are the key, as always.