YOU SAID:
No one had noticed that he fell out of tune
INTO JAPANESE
誰に気づいた彼は調子が外れて落ちた
BACK INTO ENGLISH
Fell, who noticed that he is out of tune
INTO JAPANESE
彼は調子が外れて、気づいた人落ちた
BACK INTO ENGLISH
He is out of tune, people noticed that fell
INTO JAPANESE
彼は調子が外れて、落ちたことに気づいた人々
That didn't even make that much sense in English.