Lyria 3.5 screens prompts: brand slogans and lyrics in an ad song

If you ask Lyria 3.5 for a jingle, expect the prompt to be screened. Google's guide says all prompts go through safety filters and that Lyria cannot generate specific artist voices or copyrighted lyrics. So write your own original slogan lyrics, never paste a known song's words, never name a singer to imitate, and keep the musical brief intact if a request is rejected so the retry still describes the sound you want.

What the vendor says

The Gemini API music guide (read 2026-10-04) says all prompts are checked by safety filters and that prompts which trigger them are blocked, including prompts that request specific artist voices or copyrighted lyrics. It supports custom lyrics with structural tags such as [Verse], [Chorus] and [Bridge]. The Sume Music 1.0 page mentions section markers in the form [0:00-0:30] Intro: ... and says a policy rejection should be handled by revising the flagged content while keeping the musical brief.

A brief that passes

Write the sound first and the words second. Describe emotion, tempo as a number, key, two to four instruments with texture, and one named moment in the arc. Then add the lyric lines you own. If the track should be a bed, close with "Instrumental, no vocals." and skip lyrics altogether, which removes the lyric clearance question from the pipeline.

• Use original lines, and clear the slogan separately from the audio.
• Keep the prompt under 5000 characters, the Sume limit.
• After a rejection, change only the flagged phrase.

What happens on Sume

Sume's Music Router takes the same kind of prompt and passes it to the engine, so the provider's screening still applies. Sume's docs say non-empty negative_prompt is unsupported (HTTP 400) and duration is rejected. Poll the job with Jobs and results; result.lyrics carries model-reported lyrics or a section map when the model provides one, which is metadata, not a measurement of the audio.

Closing note

Audio that passes screening is not automatically cleared for broadcast. A slogan can be someone's trademark, and a melody can resemble an existing song by accident. Listen before you ship, and keep the clearance notes with the asset.