A program designed to store listings (patch lists) and patch information for all the MIDI instruments in a particular setup. A librarian program enables a user to organize vast sets of sounds for each instrument, and to load and save different groups of sounds in each machine that may be necessary for a particular project. For example, a user could have all of the orchestral sounds for a particular instrument stored separately from the rock drum sounds. Depending upon what the instrument is to be used for on a given session, the appropriate banks of sounds can be loaded. Librarian programs were conceived and widely used in the early days of MIDI because most MIDI instruments only had enough internal memory to hold a few dozen sounds, and in many cases MIDI was by far the easiest way to get additional sounds in and out of the machine. Today the benefits of librarians are more in the domain of organization, enabling composers and producers to have easy access to large families of sounds.