AI video generators for short clips: which one, and can I use the output commercially?

I make music and I want short visuals for teasers, 5 to 10 seconds, nothing fancy. Which generator do people actually use now, and what is the deal with using the clips in something I sell or monetise?

Which tool is best changes every few months, so treat this as a snapshot: Runway, Google's Veo, OpenAI's Sora, Kling, Luma and Pika are the ones I see used for exactly your kind of clip. Try two on the free tier with the same prompt; the differences in motion and consistency are big and you will have a favourite in an hour.

On rights, three separate things people mix up:

• Can you use it commercially? Depends on the plan. Free tiers often say personal use only; paid tiers usually allow commercial use. Read the terms of the plan you pay for, not the marketing page.
• Do you own it? Under the current US Copyright Office position, footage generated purely by AI is not protected by copyright. You can use it, but you cannot stop someone else from using a similar or identical clip. Your song is still yours; the visuals are not "yours" in the legal sense.
• Will it get you in trouble? Avoid real people, real brands and anything that imitates a specific artist. Platforms also want AI-generated visuals labelled: YouTube has an altered-content disclosure, and the others are following.

Practical rule: generate the b-roll, cut it into something of your own in an editor, and keep a note of which tool and plan made each clip.

Workflow tip: keep each generated clip to 4 to 8 seconds, generate more than you need, and do the pacing in CapCut or DaVinci Resolve. Generators are still bad at "the same character across three shots", so design around cuts, not continuity.