Pocket Electronic Symphony is a smartphone symphony for a solo performer. The symphony is written as a sound generating software which acts both as the score and the musical instrument. Using this software on their mobile phone, the performer, by changing the parameters of numerous sound generation processes, navigates the successions of massive chords of synthesized sound and builds towering climaxes and suspenseful calm sections. The work tries to create a new kind of symphonic sound for the mobile age and to find new space for passionate, dramatic and grand musical expression.