Yamaha Mo 8 Manual

							Quick Guide Connecting the MO to external devices
Using the MO with computer software
121Owner’s Manual
When controlling Digital Performer 4.52:
Functions of Mackie Control assigned to [F1] – [F6] and [SF1] 
– [SF5] buttons
Some edited values are not shown on the MO display.
Press the [DRUM KIT] button to indicate the Send/Effect number in the brackets [   ] at the top of 
the LCD. 
Some parameters may not be available depending on the Effect Type. 
The [OPTION], [CONTROL], and [COMMAND] buttons on the Mackie Control correspond 
respectively to the [EDIT], [JOB], and [STORE] buttons. 
Additional operations other than those listed above are available. For details, refer to the relevant 
documentation of Mackie Control.
Please keep in mind that some functions may not be available.
Button/Controller names 
on Mackie ControlFunctions
In all modes: 
[I/O] Calls up the Mode list display.
[LEVEL METERS] Turns the Meter indication on or off. 
[SEL] Selects a channel. 
[SHIFT] + [SEL] Selects multiple channels.
[MUTE] Mutes or unmutes each channel. 
[SOLO] Sets Solo for each channel to on or off.
[REC RDY] Sets the REC RDY of each channel to on or off.
[BANK ] Scrolls through the track indication every eight channels.
[CHANNEL ] Scrolls through the track indication channel-by-channel.
[CONTROL]+[CYCLE] Turns Loop on or off. 
[TR OVERVIEW] Moves the Track Overview to front.
[MIXING BOARD] Opens the Mixer window.
[SEQ EDITOR] Starts the Sequencer Editor window.
[SHIFT]+[SEQ EDITOR] Starts the Soundbites window. 
[UNDO] Executes the Undo operation.
[REDO] Executes the Redo operation.
[SAVE] When the lamp lights, press this so that the lamp flashes. 
Press this again to execute the Save operation (lamp turns 
off). 
[MARKER] Turns the Marker on or off.
[SHIFT]+[MARKER] Opens the Marker Option window. 
[RWD] Press to continuously rewind. Press again to rewind more 
quickly. When the Marker is turned on, this operation moves 
the song position to the previous Marker.
[FF] Press to continuously fast-forward. Press again to fast-forward 
more quickly. When the Marker is turned on, this operation 
moves the song position to the next Marker.
[STOP] Stops recording or playback.
[PLAY] Press to start playback from the current point. 
[REC] Press this to start song recording. The [F]  (Play) and [REC] 
lamp are turned on during recording. 
[ZOOM] Switches between Scroll (lamp lights), Zoom (lamp is off), and 
Nudge (lamp flashes). 
[SCRUB] Turns Scrub on and off. When turned on, you can use the dial 
to move the song position. (A malfunction may occur.)
PAN mode [PAN] (or [I/O] → knob)
Knobs 1 – 8 (turning) For editing parameters. 
[DYN] + Knobs 1 – 8 
(pressing)Resets the edited parameter to the default value (center). 
[FLIP] Switches the functions of the Channel Knobs and the Faders. 
[PAN] in the PAN mode Turns the Meter on or off.
ASSIGNMENT
FADER BANKS
Track Groups/Windows
PAN / SEND
PAN / SEND
TONE
ARP FX
Dialog/Record
Transport/Project
EQ
TONE
TONE
ARP FX
ARP FX
EQ
SENDS
I/O PAN EQ BANK-L BANK-R SHIFTPLUG-INS DYN DIAL RESET KN1-4/5-8
FLIP
CHANNEL-L CHANNEL-R BANK-L BANK-R SHIFTEDIT
LEVEL METERSDIAL RESET KN1-4/5-8
SEQ EDITOR
GROUOP UNGROUP SUSPEND BANK-L BANK-R SHIFTTR OVERVIEWMIXING BOARDDIAL RESET KN1-4/5-8
OVERDUB
ENTER ESCAPE CLICK COUNTOFF SHIFTPATCH THRU CLEAR CLIP DIAL RESET KN1-4/5-8
UNDOSLAVE EXT SYNCMEMORY LINKPRE/POST ROLLBANK-L BANK-R SHIFT REDO SAVEAUDIBLE MODEKN1-4/5-8
PUNCH
MARKER EDIT GRID CYCLE BANK-L BANK-R SHIFTSELECT SOLO DIAL RESET KN1-4/5-8
CURSOR-LCURSOR-DWNCURSOR-UP ZOOM BANK-L BANK-R SHIFTCURSOR-R SCRUB DIAL RESET KN1-4/5-8
SndVal mode [SEND] (or [I/O] → knob)
Knobs 1 – 8 (turning) For editing parameters.
Cursor [UP] [DOWN] Changes the Send number. 
Knobs 1 – 8 (pressing) Sets Mute to on or off. 
[DYN] + Knobs 1 – 8 
(pressing)Resets the parameter value to the default (0 dB). 
[FLIP] Switches the functions of the Channel Knob and the Faders. 
[SEND] in the SndVal mode Turns the Meter on or off.
SndOut mode [I/O] → Knob
Cursor [UP] [DOWN] Changes the Send number. 
Knobs 1 – 8 (turning) Selects the bus for each Send of the track. 
Knobs 1 – 8 (turning)
(except when selecting a 
bus)Switches between Send PRE and POST. 
Input mode [I/O] → Knob
Knobs 1 – 8 (turning) Selects an input bus for a track. 
Output mode [I/O] → Knob
Knobs 1 – 8 (turning) Selects an output bus for a track. 
Effect mode [PLUG-IN] (or [I/O] → Knob)
Knobs 1 – 8 (turning) Selects a Plug-in Effect for each track. 
Cursor [UP] [DOWN] Changes the Effect Number. 
Knobs 1 – 8 (pressing) Turns the Effect Bypass on or off. When the bus is turned on, 
X is indicated above the Effect name. 
[EQ] + Knobs 1 – 8 
(pressing)Assigns the Parametric EQ to the corresponding track. 
[EDIT] + Knobs 1 – 8 
(pressing)
(when any track is selected)Enters the Plug-in Effect Edit mode. (Available only when the 
Plug-in Effect is selected.) Please keep in mind that some 
parameters may not be available depending on the selected 
Effect Type. Press the [EDIT] button again to exit from the Edit 
mode.
Edit mode
Knobs 1 – 8 (turning) For editing parameters. 
Cursor [UP] [DOWN] Changes an Effect Number. 
[LEFT]/[RIGHT]  Calls up the Effect of a different track. 
[CHANNEL ] Changes the parameters to be edited with the Knobs in order 
one by one. 
[BANK ] Changes the parameters to be edited with the Knobs in 
groups of eight. 
[FLIP] Switches the functions of the Channel Knobs and the Faders. 
Button/Controller names 
on Mackie ControlFunctions 
						

							Quick Guide Creating Your Original Program Set (Master mode)
Creating Your Original Program Set (Master mode)
122Owner’s Manual
The Master mode is the highest mode in the MO hierarchy, letting you instantly switch between programs you’ve created in 
the Voice, Performance, Song and Pattern modes. Use the Master mode in one of the following ways:
■ Storing your favorite programs
This lets you register settings that you often use in the Voice, Performance, Song or Pattern mode, and instantly recall the 
mode and custom settings together in a single button press, without having to first select a mode. It also lets you set up a 
sequence of custom programs—for example, when playing different songs live—and smoothly switch from setting to setting 
as needed.
■ Playing as a master keyboard
This lets you divide the keyboard into four separate sections—just as if you were playing four different MIDI keyboards. You 
can also separately play the sounds of the MO and the sounds of connected MIDI devices—all from the MO keyboard—by 
assigning each zone to a different MIDI channel. Moreover, you can use the Control sliders to tweak the sound of each as 
desired. 
Selecting a Master
The MO features 128 specially programmed Masters. Try some of these out now.
Selecting a Master is done in basically the same way as selecting a Voice. Since there is only one bank for Masters, you 
need not select a Master bank.
When the Mode is set to Voice or Performance, play the keyboard.
When the Mode is set to Song or Pattern, press the [F] button.
Creating Your Original Program Set 
(Master mode)
1Press the [MASTER] button to enter the Master Play mode. 
2Select a Master.
3Play the selected Master program.
VOICEPERFORMMASTER
Mode memorized to the current Master.
Program number (Voice number in this example) 
memorized to the current Master. 
Use the [SF1] – [SF5] buttons to call up the 
Arpeggio type assigned to each button. 
Assigned types depend on the program 
number memorized to the current Master. 
Indicates information related to the Knobs. 
The settings depend on the program 
number memorized to the current Master.  Indicates the currently 
selected Master. 
						

							Creating Your Original Program Set (Master mode)
123Owner’s Manual
Quick Guide Creating Your Original Program Set (Master mode)
Storing your favorite programs
Input a name in the [EDIT] → [COMMON] → [F1] NAME 
display.
For detailed instructions on naming a voice, refer to page 
38.
5-1Press the [STORE] button to enter the Master Store 
mode.
5-2Select the destination Master by using the data dial 
or the [INC/YES] and [DEC/NO] buttons.
When you execute the Store operation, the settings for the destination 
memory will be overwritten. Important data should always be backed 
up to a separate USB storage device (page 211).
5-3Press the [ENTER] button. (The display prompts 
you for confirmation.)
To cancel the Store operation, press the [DEC/NO] 
button.
5-4Press the [INC/YES] button to execute the Store 
operation.
Never attempt to turn off the power while an “Executing...” or “Please 
keep power on” message is shown. Turning the power off in this state 
may cause the system to freeze and prevent normal startup the next 
time the power is turned on, as well as resulting in the loss of all user 
data.
If you select another Master without storing, the currently edited Master 
will be lost. Make sure to store the edited Master before selecting 
another Master.
Playing as a master keyboard
In the Master mode, you can divide the keyboard into (up to) four independent areas (called “Zones”). Each Zone can have 
different MIDI channel assignments as well as different functions for the Control sliders. This makes it possible to control 
several parts of the multi-timbral tone generator simultaneously by a single keyboard or to control voices of an external MIDI 
instrument over several different channels in addition to the internal voices of this synthesizer itself—letting you use the MO 
to effectively do the work of several keyboards.
You can set the parameters related to the four Zones in the Master Edit mode and store the settings as a User Master.
1Select a Master to be created.
2Press the [F2] MEMORY button to call up the 
Mode setting display.
3
Select the desired mode and program number 
to register the Master. If you want to divide the 
keyboard into multiple Zones in the Master, 
set the Zone Switch to “on.”
4Name the edited Master.
Determines the mode that 
called up when Master 
number is selected.Determines whether 
Zone Switch is set to 
on or off.
Determines the program number that is called up 
when the Master is selected.
Input a Master name.
5Store the edited Master to internal User 
memory.
CAUTION
CAUTION
CAUTION
1Select a Master to be created.
2Press the [F2] MEMORY button to call up the Mode setting display. 
						

							Quick Guide Creating Your Original Program Set (Master mode)
Creating Your Original Program Set (Master mode)
124Owner’s Manual
Use Zone Edit to edit the parameters for each Zone. Use Common Edit to edit the parameters for all of the Zones.
See the next page for details and some setting examples.
Input a name in the [EDIT] 
→ [COMMON] → [F1] NAME display.
For detailed instructions on naming a Voice, refer to page 38.
Refer to step 5 on page 123.
3After setting the Mode and Program number which you wish to memorize to the Master, set the Zone 
Switch to “on.”
4Press the [EDIT] button to enter the Master Edit mode.
5Call up the Common Edit display or Zone Edit display.
6Select the menu you wish to edit by pressing the [F1] – [F5] buttons and [SF1] – [SF5] buttons, then edit 
the parameters in each display.
7Name the edited Master.
8Store the edited Master to internal User memory.
Determines the mode that is called up 
when the Master number is selected. Set the Zone Switch to “on.”
Determines the program number that is called up when the Master is selected.
EDIT
JOB STORE
COMPARE
PRE 1
A. PIANOFAVORITESPRE 2KEYBOARD
PRE 3
ORGAN
PRE 4DRUM
 KITS
GUITAR 
PLUCKED
ABCD
1234
9101112
ELEMENT  PERF. PART  ZONECOMMON
SYN LEAD SYN COMPSYN PAD 
CHOIRCHROMATICPERCUSSION
Calling up the Common Edit displayPress the [COMMON] button to call up the 
Common Edit display. 
In the Edit mode, the [DRUM KITS] button 
functions as the [COMMON] button.While in the Master Edit mode, you can switch 
between the Common Edit display and the Zone 
Edit display as shown below.Calling up the Zone Edit displayPress the desired Zone number from the ZONE 
[1] – [4] buttons to call up the Zone Edit display. 
Indicates a Common Edit display.Indicates the display for editing Zone 1.
Common EditZone 1 Edit
Zone 2 Edit
Zone 3 Edit
Zone 4 Edit 
						

							Creating Your Original Program Set (Master mode)
125Owner’s Manual
Quick Guide Creating Your Original Program Set (Master mode)
Using Zones effectively with an external tone generator
The two examples below show how to use the Zones with both the internal tone generator and a connected external tone 
generator. These instructions correspond to the steps on the previous page.
nThough all four Zones are used in the example below, you can use any number of Zones (two, three, or four). The settings are made with the 
MIDISwitch parameter ([MASTER] → [EDIT] → Zone selection → [F1] TRANS → MIDISwitch) and the TGSwitch parameter ([MASTER] → [EDIT] → 
Zone selection → [F1] TRANS → TGSwitch).
nIn these examples, the Zones are assigned to different areas of the keyboard. However, two or more Zones can also be assigned to the same area in a 
layer, from the NOTE display ([MASTER] → [EDIT] → Zone selection → [F2] NOTE).
■ Master settings with the Voice mode/Performance mode (Single-timbre tone generator mode)
■ Master settings with the Song mode/Pattern mode (Multi-timbral tone generator mode)
For each Zone, set whether or not MIDI data is transmitted 
to the external instrument.
Determine the MIDI Transmit Channel for each zone.
[MASTER] → [EDIT] → Zone selection → [F1] TRANS → TransCh
For each Zone, set whether or not MIDI data is transmitted 
to each Part of the internal tone generator.
[MASTER] → [EDIT] → Zone selection → [F1] TRANS → TGSwitch
Determine the note range of each zone.[MASTER] → [EDIT] → Zone selection → [F2] NOTE → NoteLimitH
[MASTER] → [EDIT] → Zone selection → [F2] NOTE → NoteLimitL
[MASTER] → [EDIT] → Zone selection → [F1] TRANS → MIDISwitch
Internal tone generator (Single Timbre) External tone generator (Multi-timbral)
Set the MIDI receive channel for each part.
MIDI Transmit 
Channel 1MIDI Transmit 
Channel 2MIDI Transmit 
Channel 3MIDI Transmit 
Channel 4
[UTILITY] → [F5] MIDI → [SF1] CH → BasicRcvCh = 01
For each Zone, set whether or not MIDI data is transmitted 
to the external instrument.
Determine the MIDI Transmit Channel for each zone.
[MASTER] → [EDIT] → Zone selection → [F1] TRANS → TransCh
For each Zone, set whether or not MIDI data is transmitted 
to each Part of the internal tone generator.
[MASTER] → [EDIT] → Zone selection → [F1] TRANS → TGSwitch
Determine the note range of each zone.[MASTER] → [EDIT] → Zone selection → [F2] NOTE → NoteLimitH
[MASTER] → [EDIT] → Zone selection → [F2] NOTE → NoteLimitL [MASTER] → [EDIT] → Zone selection → [F1] TRANS → MIDISwitch
Internal tone generator (Multi-timbral)External tone generator (Multi-timbral)
Set the MIDI receive channel for each part.
MIDI Transmit 
Channel 1
Part 05
Receive 
Channel 1Part 13
Receive 
Channel 2 MIDI Transmit 
Channel 2MIDI Transmit 
Channel 3MIDI Transmit 
Channel 4
[SONG] → [MIXING] → [EDIT] → Part selection → 
[F1]VOICE → [SF2]MODE → ReceiveCh 
						

							Quick Guide Creating Your Original Program Set (Master mode)
Creating Your Original Program Set (Master mode)
126Owner’s Manual
Assigning Control Change numbers to the Knobs/Sliders for each Zone
Here in the KN/CS display of the Master Edit mode, you can set how the Control Knobs and Sliders will affect each Zone. 
This lets you specify a separate MIDI Control Change number for each Knob and Slider. 
In the example above, the Control Knobs for all Zones have been set to 10 (Pan), and the Sliders have been set to 11 
(Expression). In this way, you can control the stereo position of each Zone with the appropriate Knob, and use the Sliders to 
adjust the relative volume balance among the Zones.
ASSIGN   A
PA N
CUTOFF
SWING
LOWASSIGN   B
REVERB
RESONANCE
GATE TIME
LOW MIDASSIGN   1
CHORUS
AT TAC K
VELOCITY
HIGH MIDASSIGN   2
TEMPO
RELEASEUNIT MULTIPLY
HIGH
DAW REMOTE PAGE SELECT
PAN  SEND
TONE
ARP FX
MASTER
VOLUMEZONE 1 ZONE 2 ZONE 3 ZONE 4 EQ
ASSIGN
MEFAll indicators are turned off by setting the 
[MASTER] → [EDIT] → [COMMON] → [F2] OTHER 
→ Knob/Slider parameter to “zone.” 
You can determine which Control Change numbers are used 
for the Knobs and Sliders for each zone in the [MASTER] → 
[EDIT] → Zone selection → [F5] KN/CS display. 
						

							Creating Your Original Program Set (Master mode)
127Owner’s Manual
Quick Guide Creating Your Original Program Set (Master mode)
Setting up the Master Zones to Split or Layer
This operation lets you easily determine whether the Zones of the selected Master are to be used in a Split or a Layer. 
The note range settings for each Zone can be determined by setting the NoteLimitH and NoteLimitL parameters from 
the NOTE display ([MASTER] → [EDIT] → Zone selection → [F2] NOTE). 
nZones 1 and 2 are used in the explanations here. 
1In the Master Play mode, press the [JOB] button to enter the Master Job mode. 
2Press the [F1] INIT button to call up the Initialize display. 
3Uncheckmark the box of “All” by using the [DEC/NO] button and checkmark the box of “Zone.” 
4Set the Type to “Split” or “Layer.” 
When Type is set to “Split”
Set the UpperCh (MIDI transmit channel of the upper range), LowerCh (MIDI transmit channel of the lower range), and Split Point 
(which separates the keyboard into the upper range and lower range). 
When Type is set to “Layer”
Set the UpperCh (MIDI transmit channel of Zone 1) and LowerCh (MIDI transmit channel of Zone 2). 
5Press the [ENTER] button. (The display prompts you for confirmation.)
To cancel the Job, press the [DEC/NO] button. 
6Press the [INC/YES] button to execute the Job. 
After the Job has been completed, a “Completed” message appears and operation returns to the original display.
TIP
Lower UpperSplit Point
(C3)
Layer (Upper)
Layer (Lower) 
						

							Basic Structure
Internal Structure (System Overview)
128Owner’s Manual
Basic Structure
This section gives you an easy-to-understand overview of the MO—its wide range of sophisticated features, its MIDI control 
and performance functions, and its convenient file management system for original data you’ve created with the instrument.
Internal Structure (System Overview)
This synthesizer is made up of several blocks, as shown here.
Controller block 
This block consists of the keyboard, Pitch Bend and Modulation Wheels, Knobs, Control sliders, and so on.
The keyboard itself doesn’t generate sounds, but instead generates/transmits note on/off, velocity and other information 
(MIDI messages) to the synthesizer’s tone generator block when you play notes. The controllers also generates/transmits 
MIDI messages. The synthesizer’s tone generator block produces the sound according to the MIDI messages transmitted 
from the keyboard and controllers.
Controllers supported by the MO
The controllers you can use on this synthesizer and the reference pages are as follows:
●Controllers with which the MO is equipped
Keyboard (Initial Touch) ....................................page 16
Pitch Bend Wheel .............................................page 50
Modulation Wheel .............................................page 50
Knob .................................................................page 51
Control slider ....................................................page 52
●Controllers (sold separately) that can be 
connected to the rear panel of the MO
Foot Controller.................................................. page 69
Footswitch ........................................................ page 69
MASTER
VOLUMEZONE 1 ZONE 2 ZONE 3 ZONE 4
Controller block
KeyboardControllers
Effect block
• Reverb
• Chorus
• Master Effect
• Part Equalizer
• Master Equalizer
Playback
External MIDI instrument
Audio signal flow
MIDI messages flow Playback
MIDI output
Audio (sound) output
• Voice
• Performance
• Mixing
Tone Generator 
block
DSP
Recording
Playback
Sequencer block
MIDI Sequence data• Song
• Pattern
• Arpeggio
Recording by the 
keyboard performanceKeyboard performance
Operating 
the panel 
						

							Internal Structure (System Overview)
129Owner’s Manual
Basic Structure
Tone Generator block
The Tone Generator block is what actually produces sound in response to the MIDI messages generated by playing the 
keyboard, using the controllers, and the playback of the sequencer (Song/Pattern/Arpeggio).
Internal AWM2 Tone Generator
●AWM2 (Advanced Wave Memory 2)
AWM2 (Advanced Wave Memory 2) is a synthesis system based on sampled waves (sound material), and is used in many 
Yamaha synthesizers. For extra realism, each AWM2 Voice uses multiple samples of a real instrument’s waveform. 
Furthermore, a wide variety of parameters—envelope generator, filter, modulation, and others—can be applied.
Voice, Performance, and Mixing
This instrument features three different types of programs, that form the basis for creating and playing sounds.
●Voice
A program that contains the sonic elements for generating a specific musical instrument sound is referred to as a “Voice.” 
Each Voice consists of up to four Elements (Normal Voice) or up to 73 Keys (Drum Voice). Each Voice is created by editing 
parameters unique to each Element/Key and parameters common to all the Elements/Keys in the Voice mode (page 151) or 
in the Mixing Voice mode (page 203).
●Performance
A program in which multiple Voices (parts) are combined in a layer, or in other configurations is referred to as a 
“Performance.” Each Performance can contain up to four different Parts (Voices). Each Performance can be created by 
editing parameters unique to each Part and parameters common to all the Parts in the Performance mode (page 171).
●Mixing
A program in which multiple Voices are assigned to Parts for multi-timbral play in the Song and Pattern modes is referred to 
as a “Mixing.” Each Mixing can contain up to 16 Parts (page 136). Each Mixing can be created by editing parameters 
unique to each Part and parameters common to all the Parts in the Song Mixing mode (page 189) or in the Pattern Mixing 
mode (page 202).
nThe Mixing belongs to the Song or Pattern.
Outputs the wave that makes up 
the sound.Changes the tonal quality of the 
sound output from the PITCH unit.
Controls the pitch of the sound.Controls the output level (amplitude) of the sound 
output from the FILTER unit. The signals are then sent 
at this level to the Effect block.
OSCPITCH FILTER
AMP To the Effect block
Tone Generator
Internal AWM2 
Tone Generator 
						

							Basic Structure
Internal Structure (System Overview)
130Owner’s Manual
The illustration below shows the structure and interrelationship of the Voices, Performances, and Mixings.
nThe Drum Voice Key Edit parameters do not contain LFO settings.
Keyboard Mega Voices
Normal Voices use velocity switching to make the sound quality and/or level of a Voice change according to how 
strongly or softly you play it. This makes the Voices sound authentic and natural. However, with Keyboard Mega Voices, 
each velocity range (the measure of your playing strength) has a completely different sound. For example, a guitar 
Voice includes the sounds of various performance techniques. In conventional instruments, different Voices having 
those sounds would be called up via MIDI and played in combination to achieve the desired effect. Now with Keyboard 
Mega Voices, a convincing guitar Part can be played with just a single Voice, using specific velocity values to play the 
desired sounds.
nThe Keyboard Mega Voice names are indicated as “Mega **” in the display.
VOI CE
PATTERNMIXING
SONGMIXINGPERFORM
One VoiceUp to four elements (Normal Voice)
Up to 73 keys (Drum Voice)
Common Edit parameters
Arpeggio, Effects, Controller Set, etc. 
Element 1 – 4 
or Key C0 – C6
nThis synthesizer has two types of Voices—Voices created in the 
Voice mode and Mixing Voices (dedicated for the Song/Pattern) 
created in the Mixing Voice mode.
Common Edit parametersPart Edit parameters
One PerformanceUp to four parts
One Part
Voice
Different Voice for each part
One Mixing
Part Edit parameters
Common Edit parameters
Different Voice for each part
One Part
Voice
1 –16 parts (of the internal tone 
generator)
Pitch Envelope 
Generator Waveform 
(AWM2)
Filter Envelope 
GeneratorAmplitude Envelope 
Generator Low Frequency 
Oscillator
Element Edit parameters
or Key Edit parameters
Set in the Voice Edit mode (page 153)
LFO
OSC
(Oscillator)
PITCH FILTER AMP
PEG
FEGAEG