The Casio CTK-4000 is a 61-note portable keyboard that's ideal for beginners, children, and advancing piano players alike. Just for starters, it has 570 built-in tones, including new stereo piano and acoustic instrument tones, 180 rhythms, including 74 ethnic rhythms and 20 patterns for piano play, as well as 152 Song Bank tunes, with 50 exercise phrases, to experiment with. The Casio CTK-4000 has 61 touch-sensitive, piano style keys with built-in DSP effects to add more depth and breadth to your music. Other important features include a pitch bend wheel, USB port, General MIDI, line inputs for a MP3 player, sampling, a step up lesson system, 6-track recorder, 305 music presets, and a whole lot more. This Casio keyboard also comes with a song book and music rest.
Runs on 6 "D" batteries (not included) or optional AD-5 AC power supply (see item # 338700).
61 piano-style keys
Touch Response (2 sensitivity levels, off)
48-note polyphony (maximum)
570 high-quality tones including stereo grand piano tones
180 rhythms including 74 ethnic rhythms and 20 patterns for piano play
Rhythm Editor: 10 user rhythms
Auto-accompaniment
152 Song Bank tunes, including 50 Exercise phrases
Music Preset (305 presets)
Registration (8 banks x 4 sets for 32 setups)
One Touch Preset (180 presets)
Digital Effects: 10 reverbs, 5 choruses
Preset Scale (16 scales)
Rhythm / Song Bank Controller
Song Expansion: 10 songs maximum, approximately 320 KB total
Recorder: 6 tracks x 5 songs, 1 lesson song, approximately 12,000 notes total
Sampling
Metronome
Auto Harmonize (12 types)
Arpeggiator (90 types)
Musical Information System (Backlit LCD)
USB port (type B)
GM level 1 compatible
Stereo speakers
Comes with song book, music stand
Batteries: 6 D-size (not included)
Dimensions: 40.1"W x 7.6"H x 17.8"D
Weight: 16.5lb.
Korpa 
