Program music was perhaps less often composed in the Classical era. At that time, perhaps more than any other, music achieved drama from its own internal resources, notably in works written in sonata form. It is thought, however, that a number of Joseph Haydn's earlier symphonies may be program music; for example, the composer once said that one of his earlier symphonies represents "a dialogue between God and the Sinner". It is not known which of his symphonies Haydn was referring to. His Symphony No. 8 also includes a movement named "La tempesta" that represents a storm. A minor Classical-era composer, Carl Ditters von Dittersdorf, wrote a series of symphonies based on Ovid's "Metamorphoses" (not to be confused with twentieth-century composer Benjamin Britten's "Six Metamorphoses after Ovid").