LINE 6 MIDI Mobilizer [4/12] Overview

MIDI Mobilizer & MIDI Memo Recorder Advanced Guide Page 4

Overview

MIDI Mobilizer is a hardware MID interface that allows MIDI communication between an iPhone (or

iPod touch) and the millions of hardware MIDI devices in existence. With MIDI Mobilizer, an iPhone

becomes the easiest and most portable MIDI system there is. It can be used to capture musical ideas,

backup keyboard and effects settings, and more. This guide covers the basics of MIDI, connection of the

MIDI Mobilizer, and operation of the MIDI Memo Recorder application.

What is MIDI?

MIDI (Musical Instrument Digital Interface) is what musical instruments and electronics use to

communicate with each other. Drum machines, synthesizers, digital pianos, samplers and computers

can all communicate via MIDI.

MIDI first appeared on synthesizers in 1983, and every MIDI device from that point to now is compatible

with each other. MIDI is a serial digital interface protocol that sends data that can represent what note

was played (and how hard), controller information (like a knob or button), and parameter settings. This

data is sent out the MIDI Out connection of a device, which can then be received by another device

when connected to its MIDI In connection. The standard connector used for MIDI is called a 5-pin DIN

connector (which looks a lot like the MIDI Memo Recorder icon).

MIDI does not send audio information. Instead, the information can be used by the receiving device to

create audio. For example, when a note is played on a MIDI keyboard, the data sent out MIDI conveys

what key on the keyboard was played (a Note On with a Note Number), and how hard it was played

(Velocity). When the note is released, a Note Off command is sent out MIDI. The receiving device (a

computer, a synthesizer, etc.) determines how this information will be used. If it is a sound generator, it

can create the audio with whatever sound is selected at the pitch and volume determined by the MIDI

message. If it is a device that records MIDI data (a computer, or the MIDI Mobilizer on an iPhone), it can

store the MIDI message so it can be played back to the sending device (or another device) later.

MIDI can send virtually any information about the sending device, depending on what the product’s

manufacturer chose to implement. Data that is specific to a particular device is called Sysex, which is

short for System Exclusive. This type of data is only useful for the specific product it is designed for, and

will be ignored by any other products. Sysex data is a common method of backing up the settings

and/or sound parameters of a MIDI musical instrument or effect.

Using the MIDI Memo Record application, MIDI Mobilizer can record any data that is received at its MIDI

Input. This can include note information, controllers, pedals, parameters, and Sysex data. It can then

play back the MIDI data through its MIDI Output with the same information and timing as it was

received.