Initially, this referred to the playing of music without reference to printed notation.
More recently it is also used figuratively to mean 'handle a situation in an impromptu manner',
i.e. without reference to pre-determined rules or guidelines.
Origin
The use of the word 'ear' to denote musical talent dates back to the 16th century.
William Caxton's assistant, Jan van Wynkyn (a.k.a. Wynkyn de Worde) printed this book by William Bonde - The Pilgrimage of Perfection, 1526:
"In the psalmody... haue a good eare." [The psalmody was a place where psalms were sung - what is now called the choir.]
The phrase 'play by ear' is much later. The first record of it is in an 1839 edition of The Edinburgh Review:
"Miss Austen is like one who plays by ear, while Miss Martineau understands the science."
The figurative sense came into being in the mid 20th century in the USA . the early references in that context all relate to sports, notably baseball.
For example, this story about the proposed sale of the Brooklyn Dodgers, from The Coshocton Tribune, February 1934:
"Before going further In this direction, perhaps I can believe that awful suspense by stating that I am reliably informed today that the Brooklyn Dodgers, otherwise the daffiness boys, otherwise the young men who play by ear, are for sale."
Beside of the new courses and the application of sharing student,
I found that many classmates try to reform their appearance and express their new resolution!?
For myself, I pretended that I was a cool one and behaved indifferently to this peers.
The reason I did that because of the lack of confidence on classmates and friendship.
In addition, some were declined to "depend on" other's decision to make their determination.
Is It hard for them to be independent of others?
Or am I too subject to judge the people I am tired of in the right way?
Yes, I know myself clearly.
I tried to imagine that I was desperate from other's field and stayed alone.
But I just wanna protect my soul for peace and intactness.
When I need someone's help, where are you, guys?
I don't deem the words you said for errands or routine.
If you can not pay some attention on people,
you shall not make a promise or commitment to somebody like me.
Promise is a big word no matter what kind of the form it's expressed by you or me.
Moreover, the question that why are you here and where do you go forward is clear in your mind. We are permitted to ask for some reference but not to quest what your decision is.
The chill and silent wall around me is easy to transpires.
Only if you would like to render your sincerity and inner notions to me will you get the return from my soul and appreciation.
15 credits, hmm...it was a hard work for my last semester.
I used all my efforts to survive from that.
Many of my classmates urge themselves to get 18 this semester.
I assume it should be a huge loading to me.
But why not to give it a try.
Just being silence and talking nothing are the simple way to pass the course, right?
Oops...how cynical I am.
Sound like a pathetic beginning of my new semester.
Well...let it be. I will encourage myself to study hard and to be myself.
就是那樣的純粹，總是不經意的從筆袋裡掉出來。
相見
但是，我的序號13太後面，所以不會考量
