Silvestrov often used the title "postlude" for pieces that do not need to come after anything, just as Chopin's "preludes" need not come before anything. DSCH was Shostakovich's personal motto, an abbreviation of his name in musical notes. In German notation, E-flat is "Es" and B-natural is "H" (the letter B is reserved for the note B-flat), so D-(e)S-C-H is D E-flat C B. Other composers have used similar tags, most famously Bach, whose last name spelled B-flat A C B. Rather a lot of later composers, including Schnittke, used Shostakovich's motto in tribute to him. Silvestrov uses it here in a wordless, eerily sweet song.