Lyria 3.5 better vocals and pronunciation: a listening checklist

Google's Lyria 3.5 post says the model generates higher quality lyrics with improved prompt adherence and structural awareness, and more realistic, emotionally nuanced vocals with improved pronunciation. Those are the vendor's claims for Flow Music. Sume's Music 1.0 runs on Lyria 3.5, so the same improvements may apply, but the way to know is to test a take. You can do that with one generation and one transcription.

Generate a take

Write the lyrics you want sung into the prompt, with section markers like [0:00-0:30] Intro: ... if you want structure. Sume's docs say the provider lyrics field is model-reported metadata and not an audio measurement, so it does not prove what was sung. Treat it as a hint and check the audio.

Transcribe it back

Send the finished track's URL to POST /v1/stt-1.0/transcribe with the language you expect. Compare the returned text with the lyrics you wrote. Words that differ are either a recognizer miss or a sung word that was changed. Listen to those places to tell which.

• Does every line you wrote appear, in order?
• Are names and numbers pronounced as written?
• Is the vocal style the one you asked for, or the default?
• Does the track match your named tempo and length?
• Is the audio free of words you did not write?

Keep your own notes per take. Each generation is billed once, so a rerun costs the same as the first take. What the vendor claims, and what you check, read 2026-10-06:

Keeping a record of takes

Save the prompt, the job id and the STT text next to each take. If a client asks why one version was chosen, you can show the lyrics you asked for, what was sung and what you picked.

A published vocal track may need a disclosure that it is synthetic, depending on the platform. Check the platform's own rules before you upload, and do not publish a track that sings a name or a claim you did not write.

Music 1.0 costs $0.125 per generation at the public rate. Confirm the live price in GET /v1/catalog, and do not publish a vocal track before you have listened to the whole file.