Practice often treats automatic metrics for attribution in LLM retrieval-augmented generation as interchangeable. We audit eight automatic scorers — lexical, embedding, and BERTScore baselines alongside entailment/grounding-trained models (clean and FEVER NLI, the checker MiniCheck) — across three evaluation constructs (provenance/topicality, generated-answer attribution, and fact-check entailment), asking whether any scorer transfers: stays within the 95% confidence interval of the best audited scorer on every dataset of a multi-dataset construct. In the construct with the most multi-dataset human-labeled coverage — generated-answer attribution (AttributionBench’s four source datasets, n = 1,610, with independent HAGRID, n = 2,150) — none of the audited automatic scorers does: the per-dataset metric rankings invert (Kendall τ = −0.64, p = 0.031 on AttributedQA vs. LFQA), and an off-the-shelf NLI scorer that is best on short-claim AttributedQA (AUROC 0.90) collapses to AUROC 0.53 (chance) on long-form LFQA, where BERTScore wins (0.91); the reversal persists under the tested truncation settings. This instability has a concrete decision cost: a naive "best-on-average" rule for choosing an evaluator fails leave-one-dataset-out (mean held-out regret 0.172 AUROC, worse than fixing one scorer), so metric choice should be validated on the target dataset rather than assumed from performance elsewhere. A prompt-based LLM judge avoids the chance-level collapses the automatic scorers suffer (no LFQA collapse) but is not uniformly best, ~100× costlier, and non-deterministic — relocating, not removing, the validation burden.

The application of visual-to-music generation (VTM) is rapidly growing. However, current VTM methods struggle with capturing the relationship between visuals and music in open-domain settings, mainly due to two challenges: the lack of large-scale, high-quality visual-music paired datasets and the absence of direct semantic correspondence between visuals and music. In this work, we propose CoT-VTM, a framework that distills Chain-of-Thought (CoT) reasoning to enable visual-to-music generation without paired data, while efficiently producing music aligned with visual content in open-domain settings. We first bridge the gap between visual, music, and text data using appropriate foundation models. Next, we identify key elements of the visual-music relationship and design a CoT prompt for visual-to-music mapping. To fully distill the reasoning of CoT, we incorporate latent information from intermediate reasoning steps as supervisory signals alongside visual and music supervision. Finally, we design a two-stage mapping distillation training process: the first stage uses discriminative MLP modules, while the second uses a generative embedding diffusion model (EDM). Our model achieves optimal performance on both image-to-music and video-to-music tasks. Project page: https://xxkkxxx.github.io/cot-vtm/