It's easy to forget that SHOSTAKOVICH, like so many great composers, was a gifted performing musician himself. In the Russian's case, an outstanding pianist who turned out a fair bit of music for his instrument: two sonatas, two large collections of solo pieces, two piano trios, a piano quintet, various smaller works and two concertos.
Around the time of writing the First Piano Concerto, he mentioned to a friend his temptation to return to piano performance and leave composition. The huge success of the concerto must have played some part in dissuading him, although you wonder if he might've had a slightly easier road had he done so, considering the grief that he was to get from Stalin.
It was his first concerto for any instrument and he said "this was my first attempt at filling an important gap in Soviet instrumental music, which lacks full-scale concerto-type works."
He gave no clue as to the meaning of the work, despite being asked, but wrote, in a statement of implacable banality that a modern sportsman would admire:
“I am a Soviet composer. Our age, as I perceive it, is heroic, spirited and joyful. This is what I wanted to convey in my concerto. It is for the audience, and possibly the music critics, to judge whether or not I succeeded.”
The title-page inscription of Concerto for Piano, Trumpet and Strings contains a small history of the work's development. Shostakovich explained to a student that he began writing with a trumpet concerto in mind but as things developed a piano part emerged from his imagination and gradually displaced the trumpet as the lead soloist although it remains a challenging and important support voice in the work.
The piano soloist is Behzod Abduraimov, who in an interview from a few years back revealed he almost didn't become a pianist. At age 6 he failed his very first piano examination, getting stuck in the middle of Schumann’s The Wild Horseman several times before his teacher finally told him to stop. “After that my teacher said I would never be able to play a piece on piano from beginning to end without making mistakes, ever. She said, ‘Quit music.’”
Maybe that was just some cunning reverse psychology, because he seems to be doing okay.