Although best remembered as a pianist and educator (most notably as the composition teacher of Tchaikovsky), Rubinstein was also a prolific composer; he wrote 20 operas, the best known of which is The Demon.

Rubinstein was born to Jewish parents in the village of Vikhvatinets in the Podolia Governorate, Russian Empire (now known as Ofatinți in Transnistria, Republic of Moldova), on the Dniestr River, about 150 kilometres (93 mi) northwest of Odessa.

His mother, a competent musician, began giving him piano lessons at five, until the teacher Alexander Villoing [fr] heard and accepted Rubinstein as a non-paying student.

By 1852, he had become a leading figure in Saint Petersburg's musical life, performing as a soloist and collaborating with some of the outstanding instrumentalists and vocalists who came to the Russian capital.

After a number of delays, including some difficulties with the censor, Rubinstein's first opera, Dmitry Donskoy (now lost except for the overture), was performed at the Bolshoy Theater in Saint Petersburg in 1852.

It was partly his lack of success on the Russian opera stage that led Rubinstein to consider going abroad once more to secure his reputation as a serious artist.

[15]It was during this period that Rubinstein drew his greatest success as a composer, beginning with his Fourth Piano Concerto in 1864 and culminating with his opera The Demon in 1871.

He removed inferior students, fired and demoted many professors, made entrance and examination requirements more stringent, and revised the curriculum.

He resigned again and left Russia in 1891 over Imperial demands that Conservatory admittance, and later annual prizes to students, be awarded along ethnic quotas instead of purely by merit.

American pianist Amy Fay, who wrote extensively on the European classical music scene, admitted that while Rubinstein "has a gigantic spirit in him, and is extremely poetic and original ... for an entire evening he is too much.

He was most amiable at the rehearsal... To this day I can recall how Rubinstein sat down at the piano, his leonine head thrown back slightly, and began the five opening measures of the principal theme...

The grandeur of style with which Rubinstein presented those five measures, the beauty of tone his softness of touch secured, the art with which he manipulated the pedal, are indescribable ...[26]Violinist and composer Henri Vieuxtemps adds: His power over the piano is something undreamt of; he transports you into another world; all that is mechanical in the instrument is forgotten.

After complaining of the over-three-hour length of Rubinstein's recital, Hanslick admits that the sensual element of the pianist's playing gives pleasure to listeners.

[28] Sergei Rachmaninoff's fellow piano student Matvey Pressman adds, He enthralled you by his power, and he captivated you by the elegance and grace of his playing, by his tempestuous, fiery temperament and by his warmth and charm.

His crescendo had no limits to the growth of the power of its sonority; his diminuendo reached an unbelievable pianissimo, sounding in the most distant corners of a huge hall.

Composer Karl Goldmark wrote of one recital where Rubinstein improvised on a motive from the last movement of Beethoven's Eighth Symphony:He counterpointed it in the bass; then developed it first as a canon, next as a four-voiced fugue, and again transformed it into a tender song.

The German piano teacher Ludwig Deppe advised American pianist Amy Fay to watch carefully how Rubinstein struck his chords: "Nothing cramped about him!

The fourth concert, devoted to Schumann, contained the Fantasy in C, Kreisleriana, Symphonic Studies, Sonata in F sharp minor, a set of short pieces and Carnaval.

In Moscow he gave this series on consecutive Tuesday evenings in the Hall of the Nobility, repeating each concert the following morning in the German Club for the benefit of students, free of charge.

[39] Forty-four years later he told his biographer Oscar von Riesemann, "[His playing] gripped my whole imagination and had a marked influence on my ambition as a pianist.

"[citation needed] Rachmaninoff explained to von Riesemann, "It was not so much his magnificent technique that held one spellbound as the profound, spiritually refined musicianship, which spoke from every note and every bar he played and singled him out as the most original and unequalled pianist in the world.

"[citation needed] Rachmaninoff's detailed description to von Riesemann is of interest: Once he repeated the whole finale of [Chopin's] Sonata in B minor, perhaps he had not succeeded in the short crescendo at the end as he would have wished.

[46] Rubinstein warned his students continually to guard against timidity, not to stop at a difficult place in a composition but to leave it and press ahead.

He was able, and willing, to dash off for publication half a dozen songs or an album of piano pieces with all too fluent ease in the knowledge that his reputation would ensure a gratifying financial reward for the effort involved.

[48]Rubinstein and Mikhail Glinka, considered the first important Russian classical composer, had both studied in Berlin with pedagogue Siegfried Dehn.

Glinka, as Dehn's student 12 years before Rubinstein, used the opportunity to amass greater reserves of compositional skill that he could use to open up a whole new territory of Russian music.

Rubinstein also had a tendency to rush in composing his pieces, resulting in good ideas such as those in his Ocean Symphony being developed in less-than-exemplary ways.

He was prone to indulge in grandiloquent cliches at moments of climax, preceded by over-lengthy rising sequences which were subsequently imitated by Tchaikovsky in his less-inspired pieces.

[53]Rubinstein's insistence on absolute fidelity to the printed note surprised Hofmann, since he had heard his teacher take liberties himself in his concerts.

Rubinstein replied bluntly, to the crowd's horror, "Your Imperial Majesty, if I gave you a beautiful cannon, all mounted and embossed, with no ammunition, would you like it?