How to Use Software to Enhance Your Keyboard Music-Making
Every keyboard made since the mid-’80s has a connection on the back called MIDI, which stands for Musical Instrument Digital Interface. This round jack with five pin connections revolutionized keyboard playing and music making by providing a way for all keyboards to “talk” to each other.
Every company making electronic musical instruments uses MIDI in some way; when you see MIDI listed as a feature on a product, you can be guaranteed that it will work with other MIDI devices and with various types of music software.
How MIDI works: Explaining common MIDI messages
MIDI sends various messages that describe what you’re doing at the keyboard. Play a note, and it transmits which note you play. Without getting too technical, here are the main types of messages that MIDI represents:
Note Number: Note Number is the pitch or note you’re playing. MIDI allows for 128 possible notes — many more than are even found on a piano keyboard! Each octave of a keyboard has a number, so notes are represented like C4, F3, A0, E♭ó5, and so on. The range goes from C1 to C9.
Note On/Note Off: These two commands indicate when you start a note and when you let go of the key. Taken together, they define the length of time you hold the note for.
Just like on a piano, a note can keep ringing after you let go of a key if you’re holding down a sustain pedal. MIDI accounts for this situation as well, so a sustain pedal message will override a Note Off command when necessary, keeping the note ringing until you let go of the sustain pedal.
Velocity: Velocity indicates how hard you play the note. It’s called velocity and not force because it measures the time the key takes to leave its top point of contact and reach the bottom point of contact. That speed or timing translates into a dynamic because playing more forcefully moves the key to the bottom more quickly than playing more softly does.
Control Change: Control Change is a broad selection of messages that define some other modifying action. These controllers can represent a continually moving motion or a single status, like the toggling of a switch on or off.
A number of these messages are strictly defined; for example, Control Change (CC) #7 always represents volume, such as the volume knob or slider on an audio device or mixer. Note: Pitch Bend and aftertouch are considered special messages and aren’t within the Control Change range of messages.
MIDI channel: MIDI offers 16 channels of communication, so a single output can send different messages to different devices at the same time. Only the keyboard(s) set to listen to a given channel respond to those messages, so multipart music can easily be transmitted and reproduced. A keyboard that can listen to multiple MIDI channels at once is called multitimbral.
MIDI port: To further increase the size of the MIDI network or group, a keyboard can have more than one MIDI port to communicate on. Each port adds another 16 channels to communicate on. These can be physical inputs and outputs on a device or software ports all available over the same USB port. They’re usually named A, B, and so on.
Program Change: This message is used to call up a specific sound on a keyboard or module. It simply represents a memory location in the device; any sound may be stored there. There are 128 possible Program Change values.
Bank Select: To expand the number of programs that can be called up, a group of 128 programs is considered a bank, and products can have up to 128 banks. 128 possible banks × 128 program locations = 16,384 sounds. You select a new sound in a different bank from the current one by sending the Bank Select message followed by a Program Change number.
System Exclusive: Keyboards have many things that aren’t common and can’t be standardized by a specification such as MIDI. These items are most often the parameters of the type of synthesis and other special features.
System Exclusive messages are defined by each manufacturer to manipulate and store all these individual things. This type of message can only be heard and responded to by that specific brand and model of keyboard. They are most often used for the editing and storage of sounds for a given keyboard.
Examining MIDI ports
MIDI connectors on a keyboard are usually DIN connectors You have separate in and out connections; one device transmits via an Out, and another device listens or receives the messages via an In. The hardware looks the same, so be careful when connecting devices.
You may see a third MIDI port labeled Thru; this port just passes on whatever signal comes to the In. This option is a way of connecting multiple devices in a chain, passing the signal from the first to the second to the third and so on.
More and more modern keyboards are transmitting MIDI over a USB port and may or may not have the traditional DIN ports as well. The USB port is bidirectional; it can send and receive messages over the same cable. The port is likely not labeled MIDI; it just says USB and possibly To Host. Study up on your keyboard to find out whether it supports MIDI USB functionality.
The most common misconception about MIDI is that it passes the audio signal between devices. People often connect two devices together via MIDI and then are confused when they can’t hear them. MIDI only sends control-type messages between the devices; you have to connect the device to a speaker, mixer, or even headphones to hear the sound.