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A mallet strikes a xylophone from the longest bar to the shortest. Each bar rings higher than the one before, from deep warm tones to bright high notes.

C2-1-03 Event Transition · source_body principle: Vibrating Length -> Pitch (Mechanics)
Seedance 2.0ByteDance · proprietary
Kling 3.0 OmniKuaishou · proprietary
Veo 3.1Google · proprietary
LTX-2.3Lightricks · open
Ovi 1.1character.ai · open
JavisDiT++JavisDiT · open
MagiHumanGAIR-NLP · open
Per-prompt rubric

Basic standards

Visual presence

  • a mallet
  • a xylophone

Event: a mallet strikes xylophone bars

Audio presence

  • a xylophone

Sound: a bright, pitched xylophone bar strike

Key standards

Visual physical commonsense (V-PC)

  • The mallet strikes the xylophone bars in sequence from the longest bar to the shortest, with each strike landing on a progressively shorter bar.
  • The xylophone has recognizable graduated wooden bars of clearly decreasing length, arranged in order.

Audio physical commonsense (A-PC)

  • Each successive ring has a higher pitch than the previous one, rising monotonically across the sequence.
  • The strike sound has the characteristic bright wooden timbre of a xylophone bar, not a dull wooden knock or a metallic ring.

Cross-modal physical commonsense (AV-PC)

  • Each ring onset aligns in time with a visible mallet strike on a bar.
  • Each successively higher pitch in the audio corresponds to a visibly shorter bar being struck.