Tchaikovsky wrote this piece during a summertime visit to Germany and dedicated it to Anatoly Brandukov, a pupil of the cellist who premiered (and drastically revised) the composer's Variations on a Rococo Theme. Brandukov, too, saw fit to toy with the Pezzo Capriccioso after its 1888 publication, and it is heard today in both his version and Tchaikovsky's original; the following description refers to Tchaikovsky's conception.
The piece is capricious -- not in a lighthearted way, but in its manner of toying with various aspects of a mood. That mood is initially rather dark; the work begins with a dramatic declamation from the soloist, a theme that ascends the scale at the beginning of each phrase, even though the phrase itself falls. This gives way to a rising, impulsive melody that would be eminently singable if it didn't devolve to instrumental passagework. About halfway through, a mercurial scherzo briefly takes over, but soon gives way to the main theme it had interrupted. Soon, though, the scherzo material succinctly provides the last word. This was the last completed work for solo instrument and orchestra that Tchaikovsky wrote.