The piece
Tchaikovsky finished his First Piano Concerto early in 1875. The pianist Nikolai Rubinstein, to whom he first played it, called it unplayable; Tchaikovsky changed almost nothing and dedicated it to Hans von Bülow, who gave the first performance in Boston in October 1875. Its opening is famous: four notes from the horns, then a great theme sung by the strings under the piano's chords, a theme that never comes back. Here you play that introduction as Vincent G. Stoks arranges it for piano solo, entered note by note.
The right hand's chords climb in three steps in every bar, from the middle of the keyboard to the top: get ready for each leap during the beat before, and let the weight of your arm fall without stiffness. The theme passes from one hand to the other, often inside the chords; bring it out by leaning a little more on the note that carries it.
