About that Shostakovich prelude,
perhaps you would care to hear what the composer actually wrote.
The little piece is scored for
two violins and piano;

what we performed was a (re)arrangement
where the piano part is the same, but the strings are
viola and cello,
so in some places the melodies go an octave lower than in the original.

Shostakovich Prelude (by way of Macedonia -- good on them!)