In 1906, de Hartmann met Olga Arkadievna de Shumacher, daughter of Arkady Alexandrovich von Schumacher (June 7, 1855 - June 8, 1938), Head of the Debt Repayment Commission in St. Petersburg, and Olga Konstantinovna von Wulffert (1860 - April 3, 1939), who both died in Paris.

In the same year, de Hartmann began composing what would prove to be the most ambitious production of his career – La Fleurette rouge, a ballet in 5 acts and 8 scenes, of 3 hours duration.

It was while his ballet was being performed in repertory that de Hartmann wanted to take lessons on conducting from Felix Mottl in Munich, Germany, but as he was in military service, he was barred from travelling abroad.

At that time, Grand Duchess Olga, the youngest sister of Tsar Nicolas II, liked to play the violin, and de Hartmann would sometimes accompany her on the piano.

[2] From 1912 to 1914, de Hartmann divided his time between Munich and his estate in Khoruzhivka, working on various compositions and stage productions.

When war was declared in 1914, de Hartmann was recalled to military service and moved to Tsarskoye Selo, where his regiment was located.

De Hartmann and his wife met with Gurdjieff in St. Petersburg a few times before being assigned, in late February, 1917, to the reserve forces near the Austrian front in Ukraine.

In April, 1917, de Hartmann was assigned to Masslennikov and Shmyakov, members of the State Duma, and later that month he was reassigned to travel with Rodzyanko.

In August, 1917, the Main Artillery Directorate sent de Hartmann to Rostov-on-the-Don to “speed up the production of a model of [his] system of anti-airplane machines.” (He had previously invented a kind of periscope arrangement for firing guns from the trenches without the soldiers poking their heads out to aim.

In November, 1917, while he was travelling, he fell ill with typhoid in Sochi, and was granted leave for three months, whereupon he rejoined Gurdjieff, who had moved to Yessentuki.

[3] Having establish an income from the royalties of his arrangements and film music, the de Hartmanns lived first in Courbevoie, then in Garches, south of Paris until 1950.

De Hartmann had his orchestral music conducted by such conductors as Bigot, Stokowski, and others, and his Concertos and Sonatas were played by such soloists as Casals, Tortelier, Rampal, and Alèz.

In order to be famous, it is necessary to be played on the radio.”[4] He was hampered by ill health, and spent much of his time working on publications of the Gurdjieff/de Hartmann music.

De Hartmann finished the Conservatory course under Arensky’s tutelage, learning harmony, strict style, fugue and free composition.

This is the highest compliment that I can give you.”[5] De Hartmann first met Sergei Ivanovich Taneyev at Arensky’s house when he was still at the conservatory.

He had with him some exercises in harmony from the conservatory, and Taneyev sat at the piano and analyzed them, along with Modest Tchaikovsky and Felix Blumenfeld who were also there visiting Arensky.

Taneyev was de Hartmann’s mentor during his years of doubt, when he felt that traditional music was at a dead end, and he wanted to find a new path.

Of course, I particularly liked my teacher Arensky, The Five [Mily Balakirev, César Cui, Modest Mussorgsky, Nikolai Rimsky-Korsakov and Alexander Borodin], Glazunov, Rachmaninov and others, and I still do.

In 1982, the Guggenheim Foundation premiere of Kandinsky's opera Der gelbe Klang was made possible thanks to a complete rearrangement by Gunther Schuller of de Hartmann's hitherto lost work.

De Hartmann wrote in his memoir: “I will finish my recollection of Kandinsky with the scene when I saw him for the last time, two days before his death.

They were painted during the years when no one could imagine that such catastrophes could take place, that here, on the so-called physical plane, there would be such disasters, wars and revolutions.

Perhaps here also my friend Kandinsky had foreseen the coming of a spiritual awakening, when the inner sound will be heard by everyone.”[12] From the time of his early days in Khoruzhevka, de Hartmann was interested in the Kabbalah.

As de Hartmann wrote in one of his memoirs: “As I learned later, in Taneyev’s library were also the Upanishads and Sutras, and other books connected with the field of Hindu Philosophy.

He had made a graphic design, picturing the scheme of the logical construction of the principals expounded in Spinoza’s Ethics.”[14] Undoubtedly there would have been conversations about these subjects during Taneyev’s stays with de Hartmann and his wife in Khoruzhevka.

After Taneyev’s death, de Hartmann continued his search for spiritual guidance, and in December, 1916, he met Georgi Ivanovich Gurdjieff in St. Petersburg.

Over the next few months, Thomas and Olga de Hartmann had some opportunities to meet with Gurdjieff, and he became a big spiritual influence on them.

Though de Hartmann wrote music with Eastern themes in his ballet La Fleurette rouge, this was a revelation.

After the de Hartmanns followed Gurdjieff to France, settling first in Paris, then at the Prieuré des Basses-Loges in Fontainebleau-Avon, work continued on these dances, but in a new direction – a demonstration of them, now called Sacred Dances and Exercises, was planned for the Théâtre des Champs-Elysées in Paris in December of 1923, followed by demonstrations in New York, Boston and Chicago in the United States in 1924.

During this time, de Hartmann transcribed and co-wrote much of the music that Gurdjieff collected and used for his movements exercises.

His Yellow Sound and Lumière noire communicate contrasting colours, and his Fête de la Patronne is based on a painting by Degas.