Ivories With No Strings Attached

Among piano players, the line used to be who considered themselves serious about music bought acoustic instruments - the kind seen in concert halls and living rooms. Electronic pianos were for rock musicians, or people looking for a good time. They could perform stunts, such as backing you up with a rhythm section. But each note sounded the same, no matter how hard or tenderly you touched a key.

Digital pianos have changed all that. On the market a few years, these keyboards combine the touch, sound, and expressive capabilities of acoustic pianos with the high-tech tricks of a computer. That marriage has made digital pianos among the hottest sellers in the instrument market.

Compared with acoustic pianos, which cost from $4,000 for a decent upright to $23,300 for a baby grand Steinway, digital pianos are attractively priced. Portables, often with shortened keyboards, go for as little as $399. Full-sized consoles range from $1,200 to $11,000.

PIANO TEACHER. Digital pianos create the sound of an acoustic instrument through digital sampling--the process used to produce compact-disk recordings. While even the best digital pianos can't match acoustic sound, produced by hammers striking strings, they come close. Sound engineers strike each key on a concert, grand, then store the sound digitally. Each note is recorded many times, at varying dynamic levels and speeds.

When you play a digital piano, you hear the sound of an acoustic instrument, digitally reassembled, coming through stereo speakers. Touch a key lightly, and it responds with a note of suitably quiet dynamic level. Sampling technology has become extremely sophisticated, so that the sound produced can reflect subtle changes in touch.

The real excitement of digital pianos comes from the vast array of software for learning to play or composing. Yamaha, for example, offers "guide lamps" that let beginners perform by following a flickering light above the keyboard.

Instrumental accompaniment programs also are available and are more flexible than the Music-Minus-One tapes that let you be a soloist with orchestral accompaniment. With digital software, if you can't match the orchestra's tempo, you can slow the speed with the touch of a button.

Many pianos also offer a sequencer, which lets you store, edit, and play back music to create your own composition. And most come with musical instrument digital interface, or MIDI, connectors, which let the piano communicate with a computer or other instruments. One application lets you improvise a piece and call it up as a musical score on a PC. You can even have the piano play back from that score.

Convenience is a major selling point. Digital pianos are fairly light, averaging 150 pounds, as weighed against their 500 pound acoustic cousins. There's nothing to tune or maintain. And all digital pianos can be played with headphones, making them popular with apartment dwellers and pianists who practice in the wee hours.

BELLS AND WHISTLES. About a dozen companies, including Korg, Kurzweil, and Technics, sell digital pianos. Yamaha, the leader, markets most of its instruments under the name Clavinova. Its four CLP models, priced up to $4,700, offer basic features such as additional instrument voices. The $3,345 CLP560 last year tied Kurzweil's $3,500 Mark IV for Keyboard magazine's "best bang for the buck" award. Clavinova also markets a higher-end CVP series with a broad range of options, including harmonic and rhythmic accompaniment, sequencers, and disk drive. Roland, the No. 2 manufacturer, offers a simpler HP series and a KR series with more bells and whistles.

Acoustic pianos still boast a richness and complexity of sound that digital pianos just can't reproduce. In the best of all worlds, a musician would own both.

      TRANSPOSER Shifts playing into different keys. Helpful for accompanying 
      singers.  Available on most instruments
      VOICE SELECTION Lets piano create sound of many different instruments.  
      Kurzweil's top model offers 100 voices, Yamaha's, 53
      RHYTHMS Selection of rhythmic accompaniments, including rock, boogie, samba, 
      and waltz. Only on higher-priced instruments
      HARMONIC ACCOMPANIMENT Backs up melody with bass and chord patterns. Only on 
      more advanced models, including Yamaha CVP series
      DISK DRIVE Reads 3.5 inch floppy disks.  Available on higher-priced pianos, but 
      separate components can be attached to simpler models
      SEQUENCER Digital recorder that lets you create and edit your own             
      performance.  Recording can be assembled in stages, beginning with melody and 
      following with additional layers of music