Upvoted for that lovely poem, though Li Bai is more aligned with Daoism than Buddhism.

Glad that you enjoyed the poem.

I'm nowhere near being a mathematician, though I do like what little math I've been exposed to.

What have you seen before?

I've always wondered what this 'beauty' meant. Some things seem elegant, clever, insightful - maybe distantly extrapolate-able to sublime or majestic - but 'beauty' eludes me.

According to Luc Illusie's recent Reminiscences of Grothendieck and His School

Grothendieck had a very strong feeling for music. He liked Bach, and his most beloved pieces were the last quartets by Beethoven.

I was very interested to read this because I myself am strongly attracted to Bach and Beethoven's late quartets. I can only speak for myself, but the aesthetic appeal of math for me is similar to the aesthetic appeal of Bach and of the fugues variations by Beethoven and Brahms. The key for me is the build up of grand and extremely coherent structures through layering of simple motivic elements. I find the resulting juxtaposition between the simple things that are very close to our inborn instincts and the greatest human intellectual achievements to be very poignant. This seems to be in consonance with Zagier's quotation above.

A specific musical piece that has mentioned character for me is the third movement of Beethoven's Piano Sonata No. 30.

I'd be happy to say more if you have further questions.