1. First play all of the keys:
Make sure they all operate and there are no sticking keys. While you are checking look inside to make sure the hammers are not wobbly this is a sign of problems, either loose or worn action parts. Hint clicking noises are also a sign of action component issues as well.
2. Look at the soundboard:
Make sure there are no large cracks and that the soundboard is not loose from the ribs. On a baby Grand/ Grand, you can look in from the top, a good trick is to have someone shine a drop light or flashlight from the top while you look for light through cracks from underneath. You can do the same on an upright by removing the bottom frame panel and shining a light in from the back.
3. Inspect the bridges for cracking and lifting and crown:
This is one of the more crucial area’s that is often missed by many piano tuners and lay people . To locate the bridges look for where the strings go over small raised platforms on the soundboard there are guide pins there called bridge pins. Hint: If some of the strings sound dead, tubby or buzz, the chances are the bridges are cracked or there is not enough crown. The crown is the height setting for the bridges, most piano teachers, tuners and lay people will not know how to measure this crucial setting The more expensive the piano, the more concerned you should be with this. (I hope you understand i am not recommending a clunker).
4. Look from the top and inspect the hammers for excessive wear:
Note: If the hammers are flattened down at the front (on uprights) top on grands and they are no longer tapered, then the have excessive wear and will need filing or replacement. They will also need work if you can feel impressions where the strings hit with your fingernail sometimes they can be filed and re-shaped, usually once or twice in their lifetime.
5. The most important item is the tuning pins.
If the tuning pins are loose the piano will not hold tune and this equates to a car with a blown engine, IT WILL NOT WORK without major repairs. This will be more difficult for the lay person to check without a tuning hammer and some experience. My suggestion is to try to find out the history of the piano when it was tuned last, again difficult since many instruments are neglected. A good way is to ask the piano tuners name, if someone has been taking care of their piano they should know his name immediately, if they hesitate or don’t remember that is a good reason to walk away or hire an expert!
Price: Free pianos are never free!
Before you take on a free piano have it checked very carefully, consider that it has probably been sitting there for years and has been neglected , not tuned adjusted etc, ( you are doing the beginner a favor starting them out on a poor piano).
Consider the cost:
You will have to move the piano, unless you are doing it yourself this can be hundreds of dollars depending on stairs, distance ,and difficulty. most used pianos i see from Craig’ s list and for free usually need more than one tuning and adjustments this adds up to hundreds of dollars too. Then factor in No warranty. When you add it all up especially in the case of a beginner piano you would have been better off buying from a reputable source. There are many professional restorers and dealers out there who would be able to sell you a good upright with all of this work and a warranty for under $ 1,000.00
Value
There is much to be said about the quality of the older hand built American builds. Better select hardwoods, slow grown cold climate solid Sitka spruce soundboards, rare veneers and better overall parts that were allowed to dry naturally. Today everything is kiln dried and has a tendency to warp and shrink, especially the action parts. Many of today’s pianos ( just about all) are made with particle board then cardboard on top of that followed by a thin layer of wood veneer. This is process is used very frequently on upright pianos, just about every brand i can name.