# What are stems?

Stems are the separate parts of a finished mix, kept as individual files — the voice on one, the drums on another, the bass on another. A stereo mix is those parts already blended together and no longer separable.

![Stems are the parts of a mix kept as separate files — voice, music, SFX — so any one of them can be changed alone. A stereo mix is those parts already blended and no longer separable.](https://mubert.com/tools/cast/docs-media/diagrams/what-are-stems.svg)

They matter because they are what lets someone else keep working. Handing an engineer a finished mix means they can only adjust the whole thing; handing them stems means they can turn the music down without touching the voice.

## Related

- [How do I export stems or individual tracks?](https://mubert.com/tools/cast/docs/export-stems)
- [Can I get the music as separate stems?](https://mubert.com/tools/cast/docs/music-stems)

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Source: https://mubert.com/tools/cast/docs/what-are-stems · Cast docs
Last updated: 2026-09-14