Apart from some early sketches in 1850, relating to "Siegfried's Death", Wagner composed the "Ring" music in its proper sequence. Thus, "Das Rheingold" was his first attempt to adopt the principles set out in "Opera and Drama". According to his memoirs, Wagner's first inspiration for the music came to him in a half-dream, on 4 September 1853, while he was in Spezia in Italy. He records a feeling of "sinking in swiftly flowing water. The rushing sound formed itself in my brain into a musical sound, the chord of E flat major, which continually re-echoed in broken forms ... I at once recognised that the orchestral overture to the Rheingold, which must long have lain latent within me, though it had been unable to find definite form, had at last been revealed to me". Some authorities (for example Millington et al., 1992) have disputed the validity of this tale, which Nikolaus Bacht refers to as an "acoustic hallucination".