Basically a patchlist is just what it sounds like: a list of patches. Patchlists are an important part of making software sequencers easier to use. A list of all the patch names for each keyboard in a particular set up is stored in a file (the patchlist) where the sequencer can refer to it. When set up properly it enables the user to select keyboard programs by name from the sequencer. So instead of choosing your sound on a track by looking at a list of bank names and/or patch numbers you would see the actual names of the programs. Most patch lists are a simple text file with all of the patch names listed, which means the user can easily edit them if necessary. The software maps them sequentially to the proper patch numbers of the keyboards in question. Bank one, patch one would map to the first name on the list, and so forth.