Do you want to work with traditional score notation?
In my opinion these maps are most useful when working with traditional notation scores or parts, in that you can tag patterns of text, articulation marks, and other symbols to have immediate play-back characteristics. A major advantage to using these when working with notated scores/parts, is that you won’t have stray notes scattered about in your score for things like key-switches that’ll need to be ‘hidden’ from view. They also make it easy for people who enjoy working with traditional notation to quickly enter advanced play-back instructions without going to a controller lane or list editor to ‘draw or play them in’. Such play-back instructions can also be viewed/entered/edited through lanes in the key-editor view.
If you are familiar with Finale, think of them like ‘Human Playback’ filters. If you are familiar with Sibelius, think of them like “Soundworld” soundsets.
Examples:
If you’re using an instrument that supports pedaled legato (CC68), then you could set in an expression map to always send CC68 @ 127 when there is a slur mark in score mode. When there are no longer slurs, the editor should jump back to the most recent articulation/dynamic tags (or the default tag if none are set).
You can give various score markings interpretive play-back properties. One example would be altering the length and velocity of notes marked with staccato, marcato, tenuto markings. Alternatively, you could give such score markings key-switches, program changes, or channel hops to force alternative articulations from your sample libraries to play.
You can create text pattern entries to send special commands to instruments at will. These can include instructions for things like using or not using mutes, changing tonal characteristics, swapping bow styles, and more…
Score properties (that can also be viewed/edited in the key-editor) include things like gradual hair-pin or line dynamics, tempo changes (gradual or instant) and so on. Some of these are mostly processed in Cubase itself independent of expression maps, but some of them will ALSO let you build custom tags for them in the expression maps that can compliment, or over-ride default Cubase score interpretation settings.
Expression maps can also come in handy when trying to import a really long XML score. Since Cubase doesn’t pull in dynamic markings like p, mf, or ff, as actual dynamics tags for the Score Editor when ‘importing’ an XML, then you can elect to build a simple expression map that will terrace the master volume levels of a score based on these text patterns. From there one can ‘freeze’ the score into real MIDI data, and then at least have the terraced dynamics somewhat in place for further tweaking/mixing without having to go through the entire score and ‘replace’ them all with Cubase’s own terraced dynamics tags.
Note, if you use instruments in Halion that support key switches and/or note expression, then you can have Cubase automatically generate expression maps for you. Of course you can edit such maps and add on to them as needed (and save copies for future sessions).
In Cubase, one can build key-combo commands for just about everything in the program. One can also assign most Cubase commands to MIDI events for remote control. This makes it possible to construct for yourself a really fast and easy ‘composition’ mode inside Cubase that is built around the Score Editor, and this is where making use of the ‘expression maps’ really starts to shine.
In my case I’ve decided to make use of the MPC pads on my MPK MIDI controller to build myself a powerful and easy to use ‘score step input’ mode for Cubase (using Generic MIDI Controller Maps). I rarely have to touch the computer keyboard or mouse to enter and experiment with compositions that are based on Traditional Musical scoring methods of composition! A quick example of my work flow goes something like this: Tap an MPC pad to set the length of the note or rest I want to enter. Press a key and the note pops up on the score. I repeat, wash, rinse, and suddenly I’m throwing stuff on the page exactly where I want it even faster than I can write them on paper with a pencil!. I can scroll to different staves with some cursor keys on my MPK2. I’ve also set up pads for moving the cursor around from beat to beat, as well as some for dropping in slurs/ties, and so on. Thanks to expression maps, I can use my MMO mouse (has tons of buttons on the thing that are bound to Cubase key_combos so they work with a single click) to quickly go back and drop in terraced and line dynamics, articulations, etc…and I get a basic but instant translation of my score without having to fuss about with multiple editors/windows.
It’s just fast and easy for me to start out this way when I know I’ll need a printed score of the project at some point, and all I want to do is compose without worrying about ‘playback engineering’ aspects…I’ll later ‘freeze’ scores to fresh MIDI tracks and expand such compositions into other editors for refinement IF I need a high quality, or more realistic mock-up translation. The freezing process can convert the ‘translated’ events of these expression maps into raw MIDI data that shows up in the continuous controller lanes of the key-editor where it can be viewed manipulated with extreme precision, and also becomes subject to the power and convenience of the excellent Cubase MIDI Logic Editors.
If you are clueless on how to build an expression map for a non Halion instrument (or want to alter add to automatically generated Halion maps), then the place to start is with the manual of whatever VSTi or MIDI instrument you’ll be using the map with. For example: If you intend to use something like the Garritan Marching and Concert Band library, then you’ll want to read the entire ARIA Player manual, and then read the manual that comes with the sample library.
Once you’ve read the manuals for your ‘sounds’, the layout and purpose of Cubase/Dorico expression maps should become fairly obvious. You get the tools to send just about any command that your instruments are capable of implementing, and you can implement them in a composition by simply entering the tags/symbols/text you need to trigger said commands directly on a stave, or in corresponding lanes in key-edit mode.