How Mashvio makes a mashup
You do not get a folder of famous songs. You get a job with a visible state for every step, from the two songs you supplied to one beat-locked mashup.
1. Two songs
Each side is a prompt, lyrics, or an upload. Uploads require the ownership sentence: you own the recording or you have a license that covers a public mashup, and the file is not a ripped stream. Generated songs require you to confirm you wrote the prompt or the lyrics.
The usual split is vocal from one song and the instrumental bed from the other. You can generate both, upload both, or mix the two.
2. Stems, tempo, key
The job separates a vocal role and an instrumental role. Separation is an estimate, not a studio multitrack. It then reads tempo and key. If the tempos are far apart, a small stretch is normal and a huge stretch will sound like an effect. Half-time is checked before a hard stretch.
Key is reported, not rewritten. A vocal in a distant key will still clash. Generate a closer bed instead of hoping the mixer invents harmony.
3. Mix
Align locks the stressed syllable to the downbeat. Mix writes the preview, and the lines you wrote are timed beside it. One mashup is 10 credits.
If EACHLABS_API_KEY is unset, the demo still walks every state and plays a synthesized stand-in. The screen says so. Real generation goes through EachLabs. Time-stretch stays a local ffmpeg step.
Credits
There is no free job. Starter is $14 a month or $72 a year. Creator is $24 a month or $84 a year. A failed job returns the 10 credits to the buckets they came from. A finished mashup does not.