46. It is also the reason why when we try to describe music with words, all we can do is articulate our reactions to it and not grasp music itself.

解析：主句主干It is also the reason。從句中含有一個when引導的狀語從句，意為“當我們嘗試用語言來描述音樂時”。全句意為：這就是為什么當我們嘗試用語言來描述音樂時，我們能清楚的表達對音樂的反應，但并沒有領會音樂的精髓。

47. By all accounts he was a freethinking person, and a courageous one, and I find courage an essential quality for the understanding, let alone the performance, of his works.

解析：全句為and連接的并列句。根據上文可知，he即指貝多芬。前一分句較容易，意為“據大家所說，貝多芬是個思想自由而且有勇氣的人，”后一分句中let alone“意為更不用說”，故the understanding與the performance應語義并列，據大家所說，貝多芬是個思想自由而且有勇氣的人，我發現勇氣是理解他作品的關鍵，更是表演他作品的關鍵。

48. Beethoven's habit of increasing the volume with an extreme intensity and then abruptly following it with a sudden soft passage was only rarely used by composers before him.

解析：本句雖長，但實為一個簡單句。主語為Beethoven's habit of…passage，謂語部分為was only rarely used。

整句意為：貝多芬表演時習慣性的增加他的音量，然后突然轉為柔和的節拍，前輩的音樂家很少有這種習慣。

49. Especially significant was his views of freedom, which, for him, was associated with the rights and responsibilities of the individual; he advocated freedom of thought and of personal expression.

解析：which引導的定語從句，was associated with意為“和…聯系在一起；與……有關，與……有關系”

整句意為：尤其重要的是他對自由的看法，他認為自由與個人的權利和責任有關，提倡思想自由和個人言論自由。

50. One could interpret much of the work of Beethoven by saying that suffering is inevitable, but the courage to fight it renders life worth living.

解析：interpret除了有“翻譯；解釋；說明”的意思外，還可譯為“理解，了解”。此處更適合譯為“理解”。方式狀語by saying含一個賓語從句。Render意為“致使”。

整句意為：人們會將貝多芬的很多作品解釋為——痛苦是難免的，但是與痛苦抗爭的勇氣表明生命值得活下去。