Language Point 34

He recognized that the orchestral opening to the "Rhinegold", which he must have carried about within yet had never been able to put into form, had at last taken its shape within him. (Para. 4)
Meaning: He realized that the orchestral opening to the "Rhinegold" had finally been formed in his mind. Before this, the music must have existed in his (unconscious) mind but he had never been able to express it in a clear form.