I?m looking to buy a used piano, and wonder what things I should look
for and beware of in making the purchase. Obviously the appearance of
the piano (i.e., its external condition) is one factor, and beyond
that, I am probably most concerned that the sound quality is good
(e.g., its ability to be tuned and stay in tune). Does this latter
condition vary greatly for pianos based on age and make? How can I
tell whether a piano is likely to have problems in this area? What
other factors should I consider? I welcome comments from people with
good advice or bad experiences.

I bought a 3 three old piano approximately 25 years ago...and have
been very satisfied with it. Pianos require tunings as affected by
usage and weather (humidity etc.,) and whether you have moved the
instument (ie, a house move,). Even given the age of my piano, it is
still considered a newer piano. Interestingly enough, my owner tuner
told me that older pianos don't require tunings as frequently.  He
speculated that the older woods used to build these instruments have
more resins due to being allowed to grow more naturally, in contrast
to newer woods that are "forced" to grow more quickly and therefore
have less resins.  The other issue is that all pianos sound different
and have different actions.  If you are a new piano student it might
be helpful to have your teacher or someone who has more experience
assist you in your purchase.  Hope this helps.

I seem to recall that some low-end pianos feature straight stringing
rather than crossed -- the latter being much more desirable. However,
couple of links which you might find informative.

http://www.concertpitchpiano.com/BuyingaPiano.html

http://www.pianosonline.co.uk/pol/org.paneris.pol.controller.Page/HowToChoosePiano/ChoosingPiano/ChoosingPiano_Pt4.htm

Best

I have been interested in this for a long time, and a very reputable
dealer told me once, that one of the secrets lies in how quietly a
piano will play... ie. how coherent at low levels..

Depending on your tastes and situation, you may want to consider a
digital piano with weighted keys. They are much more affordable
(especially used pianos), don't need tuning, feel like a regular piano
(and, for the record, have the correct number of keys), and sound
pretty much like a regular piano, too. Something to think about anyway
. . .

Sincerely,
Boquinha-ga

From frequent experience: Beware of sellers with grampa's 1920 upright
asking $500 for an "antique." Pianos do NOT get better or more
valuable with age--quite the opposite. Usually they require a complete
rebuilding. Look for cracks in the soundboard and corrosion on the
strings.

I took a piano tech class in college, and I've forgotten much of what
was taught -- but one thing stuck with me: that even experienced
pianists (among whom I count myself) cannot know with any certainty
the quality and condition of a piano. Before I buy a piano, I will
have the most experienced piano technician in the area (real piano
technicians, registered with the Piano Technicians Guild, should know
a great deal more than self-styled 'piano tuners') check over the
instrument and appraise it for me. Some things, such as a cracked
sound board or a stripped pin block (where the strings are tuned) are
best avoided at all costs, but can be difficult to detect. Others,
like worn felts and the overall regulation of the instrument, can be
addressed satisfactorily, but you'll want to know how much more money
you can expect to put into the piano BEFORE you make an offer. It also
wouldn't hurt at all to know a bit about the reputation, and history,
of the piano's manufacturer. Many, many name brands have been
swallowed up and consolidated by the big-name makers (Steinway,
Young-Chang, Kawai, Yamaha, etc.), and much of what is sold in the
American market is created more with an eye to its appeal as furniture
than to its utility as a serious musical instrument.

For an honest, clear-eyed overview of pianos new and used, with
specific recommendations and warnings about their manufacturers, check
out The Piano Book by Larry Fine.

Have any piano of significant cost inspected, much as you would take a
used car to an independent mechanic before buying it. The cost of
retaining a piano technician may be at least partially offset by
overlapping benefits -- he/she may include such services as moving,
tuning, refinishing or reconditioning it as part of the service
provided.

I wish you the best of luck.