A key signature indicates which notes a musician should raise or lower while playing a piece of music, and is denoted with sharp (♯) or flat (♭).
The key signature is typically marked at the beginning of the music, and is generally applicable throughout the entire piece or movement. There may be instances of key changes within the music, in which case a new key signature will be used.
The key signature helps the musician understand the musical structure of the piece. For example, if the key signature is written by 2 sharps, the key will be D Major (or B minor).
Ludwig van Beethoven, German composer, the predominant musical figure during the transition between the Classical to Romantic eras. He occupies an unprecedented dominance in the history of Western music history, and has been widely regarded as the greatest, most influential and most popular musician who ever lived.
Beethoven's music inherited the artistic atmosphere of Haydn and Mozart, penetrated the desire for dignity, vented the anger tortured by fate, and demonstrated his determination to fight with fate.
Compared to other musicians, Beethoven is effectively to interact the philosophy of life with audience through music. Although he was not a romantic, he had become the object followed by other romantics.
As a musician, Beethoven suffered from ear diseases. However, he was unwilling to succumb to fate, vowing to take fate by the throat, and continue to complete his career. In the last ten years of his life, without hearing any sound, his compositions influenced the development of music for nearly two hundred years.