Whether you're a frustrated virtuoso or just a music-loving hack, a piano is an excellent investment. A musical instrument, unlike a car or even a condominium, will hold its value indefinitely -- and a grand piano in many cases will accrue value.

Washington-area piano sales are up. At Jordan-Kitts Music, a national chain of stores headquartered in College Park, sales of grand pianos increased 40 percent for the first half of 1987 compared with the same period last year. At The Piano Man, a new- and used-piano dealer in the Baltimore-Washington area, grand piano sales now represent more than half of dollar-volume sales.

Those figures show a remarkable gain for a luxury item. Dealers are thanking the upwardly mobile. These consumers are buying pianos -- six- to eight-footers -- as never before. Granted, the price tag on a new Steinway grand is akin to the sticker on a new Volvo. But you can't put a sedan in the living room. And the best car stereo in the world is still no match for a piano when it comes to beginning your child's musical education.

I happen to drive an Escort and I've never even tasted white pizza. Still, I recently brought home a six-foot, glossy black Yamaha, G-3 series (the same model, I am told, that Elton John stroked cutting his latest album). For months before my purchase, I was overwhelmed with options -- the penalty for open-mindedness. But with a keen ear, I compared the pitches of earnest young salesmen and composed this guide for other piano shoppers:

Budget. A realistic idea of what you can afford to spend will allow you to focus on getting the best value for your buck. If your pocketbook yields less than $5,000, resign yourself to selecting a new vertical piano, a new Korean-manufactured grand or a smaller used grand by a better-known maker. A figure closer to $6,000 will expand your options significantly.

New versus used. The advantages of buying anything new are obvious, and pianos are no exception. New pianos have new parts -- not a radical concept. Replacing worn parts isn't cheap, so you should recognize that buying a used piano -- even one that's been rebuilt or reconditioned -- could cost you in the long run.

Unless you know the former owner of a piano, you can't be sure what kind of use or maintenance the instrument has had. A piano from an institutional setting has probably seen heavy use and been exposed to damaging fluctuations in climate. Buying from a private party could be safer -- if you can find a grand piano owner willing to sell.

Pitfalls notwithstanding, there are some compelling reasons to buy a used piano. The best one is that you can save a hefty 20 to 40 percent off the cost of a new one. Doug Morris, manager of the Piano Man warehouse in Alexandria, also points out that most piano failure occurs in the first year or two of the piano's life; a piano older than that will already have proven itself. Furthermore, Morris says, a "seasoned" piano -- one that's been played for a few years -- produces a warmer, richer tone than a brand new instrument.

The "gray market." The Piano Man is the East Coast's largest importer of a special group of used, late-model Yamaha and Kawai grand pianos. Owner Nick Margaritas travels to the Far East to pick grands for resale in this area from the glut of pianos on the Japanese domestic market. Once owned by Japanese dealers and institutions, these pianos have been rebuilt by independent Yamaha and Kawai factory-trained technicians.

Technically, these grands haven't been built to American specifications. Outwardly, they lack the middle pedal. And inwardly, say critics, they weren't built to weather the different moisture content of air in the United States. So far, says Margaritas, the number of failed pianos -- less than 1 percent -- makes the differences seem irrelevant.

Style. Decide whether vertical or grand is best for you. Does anyone in your home actually play the piano, or are you just interested in exposing the children to lessons? A vertical piano may be your most practical choice, especially if your living space is cramped. You can find a new, excellent quality console or studio piano for $3,500-$4,500 or a decent used one for as little as $1,500-$2,000.

On the other hand, a grand -- especially one larger than six feet -- will almost always perform better and hold its value longer than a vertical. As Rick Jordan of Potomac Keyboards explains, the action in a grand feels better, produces a better sound, and is cheaper to work on. Because the hammer is drawn back into place by gravity -- not by a spring -- a grand piano allows faster repetition and a more uniformly weighted and balanced keyboard. In addition, depressing the soft pedal on a grand piano shifts the entire keyboard to the right. Hammers strike just two of each trio of strings, which produces a soft singing tone by diminishing the percussive quality of the sound. Soft-pedaling on an upright simply moves the hammers closer to the strings, effecting a muffled version of the normal tone.

In a studio or console piano, a direct action places components on a vertical plane, using springs to return the hammer to resting position. In a spinet, vertical positioning of the components is convoluted to accommodate the tighter space. Its indirect action, with its copious moving parts, is most prone to malfunction and is a technician's nightmare to repair.

If your piano were nothing but a lavish piece of accent furniture, how would you want it to look? In the past, most pianos had a natural wood or black satin finish. But with the resurgent popularity of art deco, the glossy black finish has stolen the show. The mirror-like polyurethane coating stands up well to nicks and bumps and cleans with Windex or water and a soft cotton cloth.

The manufacturers. If "buy American" is your ethic, you have five makers to choose from: Kimball, Baldwin and Wurlitzer mass-produce fairly respectable pianos from an assembly line. Sohmer and Steinway craft pianos by hand. The used market is crowded with other American-made pianos, but their manufacturers are out of business. Every piano salesman I spoke with crooned at the prospect of owning a Steinway. (For the record, Hiroshi Kawakami, president of Yamaha Japan, has a Steinway in his home.) The oldest U.S. manufacturer, still considered the finest, produced a mere 3,000 lovingly hand-crafted pianos in 1986. The cost? About a Volvo and a half -- upwards of $20,000 for one larger than six feet.

Europe still makes a few Steinway-quality pianos too: Knight, a British piano; Bechstein, a German product; and Bo sendorfer, a Viennese wonder that sells for roughly twice the price of a Steinway.

The Far East is indisputably the piano manufacturing center of the universe. Yamaha alone produced an estimated 200,000 grand pianos last year. And annual sales of Yamaha and Kawai combined exceed sales of all five American manufacturers combined. Both Japanese companies have invested a fortune in robotics, making their factories in Hamamatsu, Japan, among the leaders in production and quality control.

Yamaha and Kawai have been exporting to the United States since the early 1960s. While travesties (action parts made of plastic instead of wood, for example) are common in pianos made before 1982, newer Yamahas and Kawais are generally bug-free. The Japanese don't even attempt to imitate the handcrafted precision of Steinway and its peers. But if you can live without a solid spruce soundboard and perfectly regulated action, you'll be happy with the quality of these pianos.

As their quality has improved, and as the world economy has shifted toward a devalued dollar, these Japanese "bargains" have increased about one-third in price. The sticker on a new six-foot Kawai is $10,000. But you can probably find the same used Yamaha or Kawai for around $6,000.

New on the scene are the Korean pianos -- in all, more than 30 manufacturers, including Young Chang (a subsidiary of Daewoo and the world's third largest piano producer), Sojin, and Samick -- manufacturer of Hyundai, Samick, Schafer & Sons and Schumann. Dealers seem to agree that the quality of these pianos, while not competitive with Japanese products, is fairly nice. The May-June 1985 issue of Consumer's Digest Buying Guide says the Koreans make the only 5-foot-4 grand worth owning. Young Chang, it seems, uses the same quality materials in this infant grand as it does in its 7-foot-4 pianos.

Because the value of the won has remained tied to the dollar, Korean pianos represent a tremendous value for American consumers.

Enlist the aid of a member of the Piano Technicians Guild. For $35, Rick Jordan of Potomac Keyboards examined a half-dozen used pianos with me, assessing the actions, pin blocks, strings, felts and crowning of the soundboards (if the soundboard loses its bowl shape and becomes flat, the piano is dead). Based on his inventory, Jordan recommended two or three pianos that were in better-than-average condition.

Unless you're just looking for a place to set roses, these inner workings of the piano are worth checking out. If you decide to buy used, hire a member of the Guild to appraise the pianos you're considering. In the Yellow Pages, under Pianos -- Tuning, Repairing & Refinishing, you'll find several from which to choose.

Check the warranty. The average manufacturer's warranty on a new piano is 10 years for all parts and labor. Manufacturers don't offer warranties on used instruments. Most dealers give 30-90-day warranties, but be sure to get it in writing. If you're considering a used piano, confine your search to established, reputable dealers or private owners.

Sound. Once you've narrowed the field in terms of technical acceptability, your final decision will rest with your ear. Whether you prefer the clear, pristine "studio" sound of the Far Eastern pianos or the complexity and unique character of the old masters, your personal taste must finally prevail.

You'll hear more if you ask the salesperson to play while you stand away from the piano. (This technique can also spare you the embarrassment of trotting out a rusty repertoire.) By the time the salesperson launches into a third verse of "Feelings," you should have a pretty good idea of how the instrument will sound at its worst. If its worst isn't half-bad ... you may have found your prize. Pam Carroll is a Washington free lance. Other money-related ideas may be sent to Moneywise, Style Plus, The Washington Post.