The Piano Concerto No. 1 in B-flat minor by Pyotr Ilyich Tchaikovsky, Op. 23, was composed in November 1874 - February 1875 at the instigation of the piano virtuoso Nikolai Rubinstein, director of the Moscow Conservatory. It was revised in the summer of 1879 and again in December 1888. It is the most famous of the three piano concertos written by Tchaikovsky.
