Mapping

In music terms, mapping refers to the process of placing individual samples across a keyboard, matched to their original pitches. In the early days of sampling, because of memory restrictions, one sample had to cover two or three notes via transposition. As an example, a sample of middle C might have to transpose up and down by a semitone or two (and sometimes even more). Today, computer-based samples are almost always limited to a specific pitch, so that now middle C would have its own dedicated sample, as would neighboring notes. Sound designers from the 1980s and ’90s will tell you how time-consuming it was to map specific samples in intervals that would transpose well and thus produce an acceptable representation of a particular acoustic or electric instrument.