The Medusa myth profoundly influenced the musical shape that Dark Angels would assume. Its pages bear the scars of Medusa's transformation, and the bitter metaphors associated with her suffering. The Piano Concerto in A minor, Op. 16, composed by Edvard Grieg in 1868, was the only concerto Grieg completed. It is one of his most popular works and is among the most popular of the genre. Grieg, being only 24 years old at the time of the composition, had taken inspiration from Robert Schumann’s only concerto, also being in A minor. Tchaikovsky’s Fifth Symphony demonstrates how convincingly he could create a large–scale symphonic work of complete technical assurance and structural equilibrium, yet wholly his own in expression.