Playing two or more different patches or sounds with the same notes. Layering can be accomplished by having one synth be a slave unit to another synth, such that they both play the same notes; setting up different patches on the different units can produce sounds that, surprisingly, do not sound like merely a mix of the individual patches but something qualitatively different (depending on the patches used). Today, it is more common to find multitimbral synths that can layer two or more voices, each sounding different patches, for each key pressed. (The tradeoff is that the synth uses more voices this way, reducing the number of notes that can be played simultaneously.) Layering can also be accomplished with a sequencer by copying one track’s notes and pasting them into another track (controlling a different synth) at the same position in time.