This article is a deep study of the technical possibilities of the modern piano and the use of this knowledge in the musical and pianistic development of the personality. The history of the modern piano begins in the XIX century. In 1823, Sebastien Erar in Paris invented the mechanism of double rehearsal. It was a double rehearsal that marked the beginning of a new history of the modern piano. Its main task is to achieve the sensation of closing a fingertip with a string. Similarly, as the ligaments of the vocalist close or the bow with the string of the violinist. Double rehearsal is a thin spring mechanism that allows you to repeatedly press a key from half or a quarter of a key's stroke without lifting your finger from the key.This mechanism drives the hammer, and the damper remains motionless. This creates a pedal sound effect. Possession of a double rehearsal allows the pianist to understand that any touch to the keyboard affects the quality and color of the sound. Touching the keyboard is called Touche - unfortunately a forgotten professional concept. Frederic Chopin owned an excellent touche, for which he was called the "Singer of the piano." Famous musician, conductor, pianist, composer, music theorist, philosopher, human rights activist, Honored Artist of Russia Mikhail Arkadyev is considered a modern researcher of double rehearsal. Mastering a double rehearsal is achieved by repeating a single sound or akorda of three, four sounds on a legato without using the right pedal. Therefore, it is necessary to learn from the very beginning and the first touch. There are many examples of the use of double rehearsal in music literature. It can be any repetition of the same sounds. She creates a variety of musical images. Possession of a double rehearsal contributes to the technical freedom of the pianist, aesthetic and physical support when playing the piano. The research of the ordered topic revealed that the sophisticated mechanism of the double rehearsal is the first and true "soul of the piano" (pedal - "friend") She (double rehearsal) contributes to the technical maintenance of the perfect performance of the musical work and requires a painstaking work as a music teacher, and his students. And this must be done from the beginning of education and education of music school students. As a conclusion of the study, it should be emphasized that today in education the personal-oriented pedagogy comes to the fore. Therefore, the upbringing, development, formation of individual and personal qualities in pupils with the means of music should occupy the current place in the work of musical schools. And this only confirms the relevance of the topic of research and requires its further development.