The String Quartets of Ludwig Van Beethoven were written over a long period of his life, from 1799 to 1826. The tragedies that occurred during the lifetime of Beethoven did not prevent him from writing these seventeen masterpieces. String quartets can be divided into three periods; middle and late beginning with the first six quartets of the op. 18 which marks his "first" works. As Beethoven's writing began to blossom with creativity and imagination, he wrote the "Rasumovsky" quartets which mark the "middle" period of his career. Finally, the last quartets (also the last works written by Beethoven) mark a milestone for various composers writing string quartets through the Romantic era and into the 20th century, especially with the use of counterpoint and harmony. This essay will show how these works were of great importance in the development of the string quartet throughout Beethoven's career, and also how their influences can be found in the string quartets of other composers. In Beethoven's early quartets, he draws great inspiration from both Mozart and his tutor, Giuseppe Haydn. Before Beethoven wrote his first quartet, he had already written several compositions because he wanted to really establish his own writing style first. Op. 18, n. 1 in F, was written for the first time in 1799 but still remains close to the Haydnesque and Mozartian writing style of the quartet, but the young Beethoven begins to place himself in his own ideas. This can be seen in the very first movement (see example 1). Example 1 – Beethoven, op. 18, no. 1, Allegro con brio, bar 13. Here Beethoven takes melodic expression to a new level: the Appoggiatura in bars 14 and 16 creates harmonic tension on a diminished seventh chord that creates “the highly expressive progression used by nineteenth- ...... middle of the sheet ...... at the beginning of the last movement. Furthermore, the decrease in the number of lines and momentum can be compared to the long tonic octave at the end of the fugue in Op. 133. It is clear that Beethoven's work is significant in the development of the string quartet to a massive extent in terms of creativity and innovation. His early quartets show great influence of those of the classical period and, with his, he influenced his contemporaries and subsequent composers. The quartets published later in his life show even greater imagination and expressive use. It is also through similar uses of structure, harmony, rhythm, and counterpoint that composers of the Romantic period and of the 20th century wrote their own string quartets. Beethoven's, however, demonstrate an enormous advance in the way string quartets are written and in the intensity of the emotions they portray. Bibliography