The secret for making a keyboard sound like an orchestra is that you must play each and every part individually. In other words, if you get the orchestral unions right, if you double up the cellos with bassoons, etc., the end result will resemble what a typical orchestra would sound like. Even today with the great samples that exist, if you put a fist full of notes down, they sound like a keyboard player playing a fist full of stringy type sounds. If you play the sounds individually and then get add the spiky down-bows, you have an orchestra. Fred's level of ingenuity came once the process was nearly finished. He would listen to the passage and say, “something is missing.” He would then add a ninth or eleventh, or some other note that I would never have guessed to add, and then before you knew it, it was Queen.