A single stem may be delivered in mono, stereo, or in multiple tracks for surround sound.
Dialog, music and sound effects, called "D-M-E", are brought to the final mix as separate stems.
[1][2][3] The dialog stem is used by itself when editing various scenes together to construct a trailer of the film; after this some music and effects are mixed in to form a cohesive sequence.
Stems prepared in this fashion may be blended together later in time, as for a recording project or for consumer listening, or they may be mixed simultaneously, as in a live sound performance with multiple elements.
Stems may also be delivered to the consumer so they can listen to a piece of music with a custom blend of the separate elements.