Keyboard Splits & Layers

THE NAME GAME

Most electronic keyboards have two basic modes of operation. In the first mode, which is often called single or program mode, one sound is assigned to the entire keyboard. In the other mode, two or more sounds can be played from the keyboard at the same time.

Just as the sound presets in a synthesizer are called programs, patches, presets, or voices by various manufacturers, the mode in which several programs are active at once may be called multi mode, combi (short for “combination”) mode, mix mode, or performance mode. All of these terms mean the same thing.

Typically the keyboard will have a separate memory bank in which to store multi, combi, mix, or performance mode setups. To keep things simple, we’ll call these setups multis. We’ll call the mode in which a multi is assigned to the keyboard multi mode.

A multi contains a number of separate slots, often four, eight, or 16. Each slot contains its own sound program and a few other settings. Again, these slots have various names, but the term “parts” is widely used. A multi can be configured to assign the parts to the keyboard in various ways.

Some keyboards have an even simpler approach: Pushing a button called “Split” lets you select one sound for the left half of the keyboard and another for the right.

SPLITS & LAYERS

One common use of multis is to assign different sounds to different regions (zones) on the keyboard. This type of multi is called a split, because the keyboard is split into separate zones. Two-way splits are the most common type, but three-way splits are sometimes useful.

If the zones overlap one another, then the parts are said to be layered, and the multi is called a layer. Layering is a great way to built truly massive sounds — imagine hearing a piano, a string orchestra, bells, brass, and timpani all at the same time when you hit a single key. Most synthesizers can produce only a fixed number of voices of polyphony at any given time, so if you play too many keys at once with such dense layering, you may find that not all of the notes will sound.

The multi may use both splitting and layering (see Figure 1). For instance, the left-hand zone might layer bass with a string sound, while the right-hand zone layers electric piano with brass.

In most instruments, the multi doesn’t contain the actual settings that are needed to create the sound programs in the various parts. The part contains only a number that tells the synth what program to use when that part is being played. If you should later edit a program and store your changes, any multi that uses that program will also change.

OTHER PARAMETERS

Most keyboards will let you transpose each part up or down individually (great for one-finger chords) and adjust the parts’ relative volumes so as to get a good sonic blend. But that’s only the beginning.

• Parts can be restricted to high or low velocity zones, so that when you play harder, a second or third sound will be added to the layer.

• Parts can be instructed to respond to, or ignore, the sustain pedal or other types of controller input. This is often useful if you want to play piano with your right hand while playing bass with the left. The bass needs to ignore the sustain pedal, while the piano needs to respond to it.

• If your synth has multiple effects processors, you’ll be able to route each part to a different effect.

• If your synth has an arpeggiator, you’ll be able to assign it to one part while playing an unarpeggiated keyboard part in a different zone.

• Each part may contain offsets for a few important settings of the sound program assigned to the part, such as filter cutoff frequency and vibrato depth. This allows the program to sound somewhat different in the multi than it does in single mode.

SEQUENCING & MASTER KEYBOARD FUNCTIONS

In many keyboards, each part of a multi can transmit and/or receive on a separate MIDI channel. In live performance, you’ll be able to play two or more external MIDI modules from the keyboard at the same time by setting each module to receive on a different channel. Some zones may transmit MIDI without making any sound of their own while others make sound without transmitting MIDI.

If you’re using an external sequencer, perhaps one that runs on your computer, you can set up a multi so that its parts respond on various MIDI channels. The sequencer can then “play” each part individually from a different track.