The sheer complexity of a piano’s mechanism is often overlooked by nature of it being hidden from view. It’s surprising the number of times I’ve removed the front board of an upright, or the keyboard out of the grand piano and the piano teacher states: “I’ve never seen that before!”

I actively encourage music educators to learn how the inside of a piano works. There’s no expectation to become an expert – that’s what piano technicians are for – but a basic understanding of how to assess a piano’s quality and condition is an important skill to have.

How do we know if a piano is suitable for education? The most comprehensive way is to engage the services of a piano technician to carry out a condition report. Before we do that, however, here are some basic points to check over when assessing a piano:

Age: How old is the piano? Printed on the iron frame of most pianos will be a serial number unique to that piano. A quick search online for a piano age calculator should help you here.

Keyboard: What condition are the white and black keytops in? Chips, uneven heights and rough surfaces negatively affect the playability and feel of a piano.

A less obvious aspect to watch out for is the state of the key bushings. Key bushings (Figure 1) are made from cloth which sit within the mortises of the wooden keys, between the wood and the pins on the key frame. Pick a few sample keys, hold one down halfway through the keystroke and wiggle it from side to side. If there is more than 1mm of movement in either direction, the key has worn front bushings. The job of these bushings is to smoothly guide the key in the vertical plane. As they wear, the keys are able to move in a horizontal plane, giving the keyboard a “loose” feeling. This affects fine control of piano playing quite substantially – if you’ve spent a lot of time playing on a worn-out keyboard, you’ll definitely notice the difference when you play on one in good condition!

As piano mechanisms are mostly constructed with wood, felt, cloth, leather and other organic materials, the previously mentioned aspects of age and wear start to take their toll. Without launching into a lecture on piano regulation (grand pianos have ~35 procedures, per key), there are some basic things to look out for.

Try and analyse how the keyboard feels. How softly can you make the hammer strike the string? Is this consistent across the keyboard? By lifting the top lid of an upright or looking between the strings on a grand, slowly depress a key and watch the hammer move. As it nears the string at a certain point, the hammer will disengage and fall back. The distance between hammer and strings at which the hammer disengages is called “let-off” and should be 1–3mm. If this distance is significantly greater and/or is inconsistent across all the hammers, the keyboard will feel unpredictable and difficult to control in the pianissimo register.

Other regulation procedures – such as key height, key depth and “hammer to string” distance are equally as important, but are difficult to assess without training, so these would be best checked over by a piano technician.