 The composer presented a copy of the score to Dmitri Shostakovich, its dedicatee, at the 1962 Edinburgh Festival.The work takes the principle of the passacaglia or chaconne – namely, strict variations on an unchanging subject, usually a ground bass, and applies it across a very large single-movement structure that divides into a cumulative design of many different musical styles and forms.It is based on a 13-note 'ground' derived from the musical motif "D, E-flat, C, B"