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Creating remixes of tracks or having tracks mixed by a mix engineer are common instances where you would need to work with or create stems/parts.
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each drum sound, these may also be referred to as parts. If each individual track is rendered as a separate audio file, e.g. For example, a song might be split into five separate stems: vocals, guitars, bass, keyboards and drums. A stem is a discrete or grouped collection of audio sources mixed together.
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