Expression Maps in Cubase

Expression maps in Cubase

Cubase expression maps are basically improved versions of key switching. You can map all your existing key switches in the expression map setup and label them accordingly. Those articulations can now be found in the Articulations/Dynamics controller lane inside the MIDI editor. Now you can simply draw a bar of the articulation you want and audition the result.

Keyswitches 

Sample libraries often make use of keyswitches (Figure 1), which are usually used to describe keys (MIDI notes) that are not used to trigger specific samples, but to control the behavior of a Virtual Instrument (VSTi) in a different way. For example, in the Native Instrument Choir Collection there are certain keys on the lower range of the keyboard that control which vowel is sung by the choir, while in the Orchestral Collection there are keys that control the type of articulation (e.g., staccato, sforzando) performed by the musicians. Under the hood, in both cases, the keyswitches are actually used to select a different sample set to be triggered by the rest of the keyboard. For many keyswitching instruments, the pitches to which the keyswitches are assigned will be displayed on the onscreen keyboard. Typically, these are defined in the lowest octaves of the keyboard.

There exist ‘latching‘ and ‘non-latching’. keyswitches. Non-latching keyswitches are active for as long as the key is held, i. e. the particular sample plays until the key is released. On release, the default (first) sample is played again. Latching keyswitches stay on until the next key is pressed.

Since keyswitches are midi notes, this potentially causes a problem when, for example, you transpose all midi notes on a track. Transpose will also transpose the keyswitches making them sound as real notes and not acting as keyswitches any longer.

Figure 1: keyswitches in blue (midi notes C0 – D#1; see music note numbering) trigger different articulations (middle part) of one of the EWQL Symphonic Orchestra instruments.

Use of expression maps.

Instead of keyswitches you can define Expression Maps that allow you to set up a map for all of your articulations to a specific key. If you use Expression Maps you don’t have to enter to keyswitches as midi notes but you can define the articulation for every midi note by simply using the Pencil tool in the Articulation lanes in the MIDI editor (Figure 2). The keyswitches are tight to the midi note and, consequently, if you move the midi note then the articulation in the lane is moved with it.

Figure 2: Spitfire BBSCO template.  Left. In the project window there is an empty MIDI part for the ‘Shorts’ samples of the violin. In the inspector you see three articulations that are defined (Spiccato, Staccato, and Spiccato CS) assigned to MIDI notes E-2, F-2, and G-1 respectively. Right.  Opening the MIDI part in the midi editor, you can now open a lane for the Articulations and draw in the articulation you want to use for each MIDI note. In this way you don’t have to enter the MIDI notes in the editor part. 

Defining expression maps.

The Expression Map Setup window allows you to load, create, and set up expression maps (Figure 3). In this window you can (de)activate the Latch Mode but this option is system-wide, i.e., you can not have different values for different expression maps, nor for different articulations. This might best be set to non-latching such that when an keyswitch (articulation) is released, the default sample sounds again. However, this requires that for everynote you need to make the articulation explicit (see [here]).

Figure 3. Defining expression maps. 

Articulations

Musical articulations define how specific notes are sung or performed on a given instrument. They can also define the relative volume of notes or the changes in pitch. The following two articulation types are available:

• Directions: Directions, such as pizzicato, are valid for all notes from their insert position to the insert position of the next direction. They are applied to a continuous range of notes, or even to an entire piece of music.
• Attributes:  Attributes, such as accents, or staccato, are valid for single notes.

Note that assigning ‘Direction’ to a keyswitch may override/conflict with non-latching articulations. Thus, check carefully the behavior of your expression maps.

Separate tracks vs Key Switches vs Expression maps

If you want to use the different articulations of your sample library (VST instrument), then you have three options:

1. Setup a different track for each articulation
2. Use keyswitches
3. Use Expression maps

I think it is mostly a matter of personal preference, but having a different track for each articulation allows to process (e.g., Eq, compression) each articulation individually and to send them out to different mix or effect busses. This at the expense of potentially ending up with large number of tracks in your project.

If you use the Cubase Score editor (or any other scoring software such as Dorico) then keyswitches end up in the score as very low notes. This may not  be what you want. Using expression maps does not give this problem. Another potential problem with keyswitches is that if you start playing a MIDI track not from the beginning then it may miss a keyswitch (if it doesn’t chase backwards) and, consequently, plays the wrong sound.

Videos

Video: Expression Maps (for Key Switches) in Cubase 12

References

• Cubase expression maps @Steinberg
• Expression maps in Cubase 5 (Sound on Sound)
• Expression maps in Dorico