Selecting a sound is as easy as keying in a number, and recording virtuoso performances is simple with the built-in recorder. The included Yamaha Education Suite and USB connectivity add functionality.

Just as on a traditional acoustic piano, the keys of the lower notes have a heavier touch, while the higher ones are more responsive to lighter playing. The keyboard’s sensitivity can even be adjusted to match your playing style. This Graded Hammer technology also enables the instrument to provide authentic touch in a lightweight instrument. The matte finish of the black keys enhances the keyboard’s luxurious appearance.

Amazingly Realistic and Dynamic Sounds
 
Yamaha’s highly acclaimed Sweet! and Cool! Voices deliver incredibly natural and very dynamic sound. Use the Pitch Bend wheel and hear these Voices—especially the Sax and Trumpet—truly come alive.

Live!, Cool! and Sweet! Voices

Live!, Cool! and Sweet! Voices gives you a huge palette of acoustic and electronically amplified instrument sounds. A blend of long, stereo and multilayered samples is used to fully capture the natural presence, resonance, expression, and vibrato of the real instrument.

Digital Signal Processor (DSP)

237 types of the DSP effect can be added to the Main and Dual Voices. These range from reverb-like ambience effects to distortion and other dynamic processing tools that let you enhance the sound, or completely transform it.

Easy Song Arranger

In addition to each song’s default style, you can select any other style to play the song with the Easy Song Arranger feature. This means that you can play a song that is normally a ballad, for example, as a bossa nova piece or hip-hop tune, etc. You can create totally different arrangements by changing the style with which a song is played. You can also change the song’s melody Voice and the keyboard Voice for a complete change of image.

Performance Assistant Technology (P.A.T.)

Play along with a song on the instrument’s keyboard and produce a perfect performance every time—even if you play wrong notes. All you have to do is play on the keyboard—alternately on the left- and right-hand ranges of the keyboard, for example—and you’ll sound like a pro as long as you play in time with the music.

Music Database plus External Files

You want to play music in your favorite style, but you’re not sure how to select the best Voice and style for the type of music you want to play? Simply select the appropriate style from the Music Database. The panel settings will automatically be adjusted for the ideal combination of sounds and style! Furthermore, this instrument allows Music Database files transferred from a computer or stored on a USB flash memory device. These files can be used in the same way as the internal Music Database.

USB TO DEVICE

The USB TO DEVICE on the instrument allows you to connect USB memory devices such as flash drives or hard drives, enabling you to save or load registrations and user songs created on the instrument, as well as read data from the connected device such as MIDI files or style files.

USB TO HOST

Dive in and take advantage of the wide world of computer music software. Connections and setup are exceptionally easy, and you can play back your computer-recorded parts with different instrument sounds - all from a single instrument.

Performance with Music Notation Display

When you play back a song, the corresponding score will be shown on the display. This is a great way to learn how to read music. If the song contains lyric and chord data, the lyrics and chords will also appear on the score display.

Yamaha Education Suite (Y.E.S.)

Yamaha Education Suite (Y.E.S.) is an advanced set of helpful learning tools built into the instrument, letting you teach yourself how to play and perform. Y.E.S. helps you master a song with easy lesson steps. Each lesson can be done in isolation with either your left hand or right hand, or both.

Features

 88-key Graded Hammer Standard keyboard with matte black finish key
 535 Voices
 Polyphony: 64
 Piano voice quality: new Live! Grand Piano
 Featured voices: 4 Pianos (Live! Grand Piano, Live! Pop Grand, Live! Warm Grand, Ambient Grand Piano), 9 Live! Voices / 7 Cool! Voices / 8 Sweet! Voices
 Reverb: 35 types
 Chorus: 44 types
 DSP: 237 types
 Preset Master EQ: 5 types
 Dual and Split effects
 Harmony/Echo: 26 types
 Panel sustain in menu
 Overview demo
 Easy Song Arranger
 300 or more songs in the database
 Metronome
 Yamaha Education Suite: Waiting, Your Tempo, Minus one, Repeat & Learn
 Pitch Bend Controller
 Chord Dictionary
 Performance assistant technology: Chord, Melody, Chord / Free, Chord / Melody
 One Touch Setting Including Voice List
 Registration Memory: 4 Pads x 8 Banks
 Pedal: Sustain
 Flash memory
 External Storage Device (USB Flash Memory)
 Compatability: GM, XG lite

Playback
 Number of preset styles: 165
 User Styles
 Compatible file format: SFF
 Variations: 2
 Fingering: Multi / Full Keyboard
 Number of preset songs: 30
 Compatible file format: SMF

Recording
 Number of songs: 5
 Number of tracks: 6 (5Melody + 1Chord)
 Compatible File Format: No (Original File Format)
 User Song to SMF Converter
 Score Display
 Lyric Display
 Compatible data format: XF

Overall Control
 Tempo: 11 to 280
 Transpose: -12 to 0, 0 to +12
 Tuning: -100 to +100 cents
 Pitch Bend Range: 1 to 12

Display
 Type: Full-Dot LCD 320 x 240 Dots
 Size: 98mm x 65mm
 Backlit

Aux. Jacks
 Phones (/Output)
 DC IN
 Footswitch
 Pedal Unit
 USB TO HOST
 USB TO DEVICE (front panel)

Outboard Content
 Song: XG/XF Songs (CD-ROM including), Pianosoft Solo, DMN lite, Performance Guide
 Others: Style, Music Finder Record

Amplifier / Speaker
 Amplifier: 6W x2
 Speaker Size: 12cm x 2 + 3cm x 2cm

Yamaha DGX 640 88 Key Digital Piano Includes:

 wooden stand, PA150 adapter, and sustain pedal

Yamaha digital pianos comparison

Reviews on Web

 Youtube

 Harmony Central (en)
 Thomann (de)