[Lib] I believe you're thinking of Saint-Saens' Dans Macabre (doodoo, doodoo, doodoo, doodoo....) and see my second answer to Tuj, which should have narrowed it down a bit for you.
What a great game this is! Once we've calmed down and are focusing on just one at a time. Shame Roobarb and Custard has already gone, because that it the greatest theme tune of all time.
[Btd] The "Warsaw Concerto" was written by Richard Addinsell for the film "Dangerous Moonlight" and, whatever its merits, has nothing to do with Tchaikovsky or even Rachmaninov. I think you mean the B flat minor concerto, but I don't think it is. I had no idea that you'd all find my little snippet so hard. Shall I reveal all, or take three more guesses?