tl;dr: Two frontier models (Claude "Fable 5" and GPT "5.6 Sol") were given an autonomous tool-calling harness, a song, and $25/$100 budgets to research, generate, and edit a full music video via ffmpeg. All four runs completed valid videos, but quality was mediocre across the board: characters drifted between shots, lyrics were interpreted too literally, tempo matching was weak, and none of the models iterated on their edits or reviewed their own footage. Claude cost significantly more in tokens (~30-40% of total), while GPT-5.6 Sol was the more inventive editor, mixing multiple video models and adding overlays.