This part hasn’t much to do with my work, but on occasion I am asked for advice about buying a used piano. Here are some things to consider:
If it is for you, and you are just playing for fun, the choices are less critical than if you are buying for a kid taking lessons. For you, the most important thing is that the piano can be tuned and that every key works.
Basic inspection:
Open up the piano so you can see the hammers, strings, and tuning pins. Extreme rust on the strings and tuning pins is not good. Strings will be more prone to breaking.
Play each note and watch the hammers move. If it is just one or two, that’s not a big problem. If a bunch hang up or are slow to return when you let go of the key, that’s an expensive problem.
Listen to each note. Most notes have three strings tuned to the same pitch. If the note sounds a bit out of tune, that’s ok. If one note sounds like you are playing two notes together, that’s a big problem.
Depress the pedal. Make sure that all the felt dampers (on an upright they are in a line under the hammers) lift off the strings roughly at the same time. If they lift together, if not exactly all the way, that’s ok. If some or many don’t lift at all, that could be expensive.
Finally, if you are planning on playing the piano with other instruments, bring something with a pitch reference: you can download a wave file that plays an ‘A’ on your phone, or a keyboard app, or a pitch pipe. If the reference pitch sounds like a different note than the one the piano plays, the piano is not at pitch. Depending on how the piano is, and how much rust is present, it may not be healthy enough to tune it up to pitch.
Further tests if it is for a student taking piano lessons:
In addition to the tests above, it is critical to the student that the piano is at concert pitch. Otherwise, they will think that they are playing the wrong notes when they switch to the teachers (or the examinationer’s) piano. This will really hold them back, especially once they get into Grade 6 levels and beyond. Students also need a piano that has decent tone. If you don’t know pianos, find someone who does. Or better yet, hire a piano technician to do an inspection. Small apartment sized pianos usually have bad tone and bad touch—Yamaha and Kawai small uprights being the exception. Big old ‘grandfather’ pianos have a bigger sound, but the actions from 80 years ago are often so far from having the ‘feel’ of a modern piano that it will hold the kid back. Kids who are asked to play on a lousy piano “until they see if they ‘take’ to lessons,” won’t. I can’t tell you how often I am see that the kids whose parents spent good money on a new or very good used piano are the ones that keep taking lessons. The kids that are given a kijiji special usually last about 6 months. It is like trying to enjoy reading with foggy glasses.
Oh, and if you were thinking that buying a cheap keyboard for that aspiring student is an alternative, it isn’t. The feel is wrong, the sound is wrong, and most teachers find that the student goes nowhere quickly.