Prelude in D-flat Major Op. 49 No. 1 by Alexander Glazounov. Sheet music and recordings of thousands of piano pieces by Alexander Glazounov and many other famous composers to view in your digital device, print out or listen to. Prelude in D-flat Major - Op. 49 No. 1 is a piece by the late romantic composer Alexander Glazounov. The composition was first published in 1894 and is included in Miscellaneous pieces by Glazounov.