"Good" (quantum) number and 恩賜之絲竹

"Good" quantum number.
We often meet this term on the fundamental textbook of QM or QP.
But, when one is who study QM the first time, or, even is the researcher would not have idea for this term.

Like as Configuration Interaction, I might say that is the off-diagonal parts.
But, 「不協和音」is the best for my ordinary-level brain.

滋賀の古屋ピアノ教室様
https://furuyapiano.com/music/5798furuyapiano.com

The period Pythagoras lived is between B.C. 582 ~ B.C. 496.
孔子's is B.C. 551? 552? ~ B.C. 479.

They both may, as the nature philosopher, loved music specially that without off-diagonal part as "Good" number.

Conclusion , 宮中下賜給張掄居士絲竹.

cited from 詩詞大全sama
iccie.tw

~~
阮郎歸·金烏玉兔最無情
[作者] 張掄 [朝代] 宋代

金烏玉兔最無情。驅馳不暫停。
春光才去又朱明。年華只暗驚。
須省悟，莫勞神。朱顏不再新。
滅除妄想養天真。管無寒暑侵。