Modest Tchaikovsky set about creating the museum with extraordinary energy. He not only preserved all the items valuable for history that remained in the house after the death of his brother, but also collected a huge number of Pyotr Tchaikovsky's manuscripts: his letters, musical autographs and many other unique materials. Great help in this was provided, first of all, by the composer's closest friends and his students: Laroche, Kashkin, Taneyev, who not only collected relics, but also attracted others to this work.
The museum was opened a year after the death of Tchaikovsky. Modest Tchaikovsky, the creator, the first director, curator and researcher in one person, laid down practically all the directions of the museum's activities, which were then developed, and above all, such as preservation, collection, scientific work and propaganda. In 1916, by the bequest of Mikhail Tchaikovsky, the museum was transferred to the Moscow branch of the Russian Musical Society, on the condition that it be preserved and maintained following the example of the Mozart house in Salzburg and the Beethoven house in Bonn.
During the years of the revolution, the House in Klin was going through troubled times: a certain anarchist Doroshenko moved into it with his family, who in the morning used to shoot from a revolver the portrait of Pope Innocent, which decorated the walls of Modest Ilyich's bedroom, then the Klin new government wanted to transfer the first floor and an extension for some public institutions. But the House-Museum was saved by the intervention of the department for the protection of monuments of art and antiquity of the People's Commissariat of Education of the RSFSR - in 1918 the museum was issued a certificate of protection.
The years of the Great Patriotic War became another tragic page in the history of the House-Museum. Back in early August, taking into account the heated situation, the government decided to evacuate the museum to the homeland of Pyotr Tchaikovsky - to Votkinsk. The Tchaikovsky House was badly damaged by the invasion of the Nazis, which caused significant damage to the building. They turned the first floor into a garage for motorcycles and a saddlery workshop, and on the second floor, in the rooms of Tchaikovsky and his brother, they set up soldiers' barracks.