which it must have been specially designed." This theme appears in five different orchestrations throughout the movement, with changes of mode (major to minor), dynamics (forte to pianissimo) and a blending of instrumental colour that ranges from boldly stated tutti passages to the most subtle and differentiated episodes, where instrumental sounds are combined often in quite unexpected ways: The theme first appears in the minor mode during the orchestral introduction, performed using staccato articulation and orchestrated in the most delicate and enchanting colours: This is followed by a more straightforward version in the major key, with horns accompanied by strings. The theme is now played legato by the horns, accompanied by a sustained pedal point in the bassoons. The violins simultaneously play an elaborated version of the theme. (See also heterophony.) The timpani and pizzicato lower strings add further colour to this variegated palette of sounds. "Considering that the notes are virtually the same the difference in effect is extraordinary": When the solo piano enters, its right hand plays a variant of the minor version of the theme in a triplet rhythm, with the backing of pizzicato (plucked) strings on the off-beats: This is followed by a bold tutti statement of the theme, "with the whole orchestra thumping it out in aggressive semi-staccato. : The minor version of the theme also appears in the cadenza, played staccato by the solo piano: This is followed, finally, by a restatement of the major key version, featuring horns playing legato, accompanied by pizzicato strings and filigree arpeggio figuration in the solo piano: Fiske (1970) says that Beethoven shows "a superb flood of invention" through these varied treatments. "The variety of moods this theme can convey is without limit." Berlioz The most significant orchestral innovator of the early 19th century was Hector Berlioz. (The composer was also the author of a Treatise on Instrumentation.) "He was drawn to the orchestra as his chosen medium by instinct … and by finding out the exact capabilities and timbres of individual instruments, and it was on this raw material that his imagination worked to produce countless new sonorities, very striking when considered as a totality, crucially instructive for later composers, and nearly all exactly tailored to their dramatic or expressive purpose." Numerous examples of Berlioz's orchestral wizardry and his penchant for conjuring extraordinary sonorities can be found in his Symphonie fantastique. The opening of the fourth movement,