Hector Berlioz was a revolutionary French composer known for his innovative orchestration and his 'programmatic' music—music that tells a specific story. His masterpiece, 'Symphonie fantastique' (1830), was inspired by his obsessive love for an actress and included a 'March to the Scaffold' and a 'Dream of a Witches' Sabbath.' Berlioz was a pioneer in the use of large orchestral forces and unusual instrumental combinations. He wrote the 'Treatise on Instrumentation,' which became a foundational text for later composers like Strauss and Mahler. Despite his genius, he was often misunderstood in his own country and spent much of his life working as a music critic to support himself. His grand operas, like 'Les Troyens,' and his massive choral works, like the 'Grande Messe des morts,' are monuments of the Romantic era.