It is generally agreed that it was the orchestral genius of Hector Berlioz that was responsible for the invention of the modern orchestra as we think of it. Up to his time composers used instruments in order to make them sound like themselves; the mixing of colors so as to produce a new result was his achievement. Berlioz took advantage of the ambiguity of timbre that each instrument has in varying degrees, and thereby introduced the element of orchestral magic as a contemporary composer would understand it. The brilliance of his orchestration comes partly by way of this ability to blendm instruments -- not merely to keep them out of one another's way. His skillful writing for the individual instruments disclosed the unsuspected characteristics of their different registers. The particular registers chosen for each group of instruments enhances the sheen and sparkle of the combined texture. Add to this incredible daring in forcing instrumentalists to play better than they knew they could play.He paid the price, no doubt, in hearing his music inadequately performed. But imagine the excitement of hearing in one's inner ear sonorities that had never before been set down by any other man. It is the subtle calculation of these masterly scores that convinces me that Berlioz was more, much more, than the starry-eyed romantic of the history books.
It would be easy to point to specific examples of Berlioz' orchestral during. The use of the double basses in four-part pizzicati at the beginning of the March to the Scaffold the "Symphonie Fantastique"; the writing for four tympani, also in chordal style, at the conclusion of the movement that precedes the March; the use of English horn and piccolo clarinet to typify pastoral and devilish sentiments, respectively; the gossamer texture of Queen Mab with its Debussian harps and high antique cymbals; the sensitive mixtures of low flutes with string tone at the beginning of the Love Scene from Romeo -- these and numerous other examples prove that Berlioz brought to music an uncanny instinct for orchestral wizardry.