1) Rock music duo 
Fading one element or track of a mix out, as you fade another one in.
Lighting or sound change where some of the channels increase while others decrease. (UK) 
The gradual mix of sound sources accomplished by the simultaneous manipulation of two or more mix console faders. (Post Production)
Fading one element or track of a mix out, as you fade another one in.
To gradually fade out one sound while fading in another so that a seamless transition is made between the two sounds.
A change from one lighting or sound state to another without darkness or silence.
A lighting action in which a particular light cue fades down as the next light cue fades up.
Fading out of one scene and into another. There is a moment of interruption between the scenes.