Piano Key Stuck Down: Eight Causes, Cheapest First

You typed "sticky piano key" into a search box and got humidity advice. That's not the symptom you have.

A sticky key is slow or mushy and comes back up on its own. A key that stays down parks at the bottom, an inch below its neighbors, and waits there until you lift it with a finger. Those are different parts and different bills, running from free to a rebuild.

Answer these four questions first

Did the note sound? A note that spoke normally means the action worked going down and something failed coming back. A silent, weightless drop means the connection between key and hammer is gone. Causes 6, 7 and 8 below are the silent ones.

Does it lift with a fingernail? Gritty and tight means friction. Free, then correct once, then stuck again means a part stopped resetting, which is cause 4.

One key or a run of neighbors? Friction travels in groups of two or three. Broken parts are one note.

Overnight or over a humid week? Overnight points at an object or a break. A wet July points at the wool.

1. Something wedged between the keys (free)

A quarter drops straight through the gap between two keys, and so does a guitar pick. Richard's Piano Service lists what turnsTurnAn ornament consisting of four notes: the note above, the main note, the note below, and the main note again.The Savvy Take: A Turn is like drawing a circle around a note. It decorates the pitch. Don’t rush it so much that it sounds like a glitch; it should be a graceful curl.View in glossary → up inside pianos: paper clips, coins, can pull tabs, stamps, stickers, bobby pins, straight pins, rubber bands, pencils, and mouse nests with the droppings that come with them. The object blocks the key from rising, or holds it canted so a bushing binds. It shows up instantly, on one key or two adjacent, and feels wedged instead of draggy. Sight down both gaps with a flashlight.

2. Swollen key bushings, the August special ($55)

Every key rides on two steel pins: a balance rail pin through a cloth-bushed hole at the key's fulcrum, and an oval front rail pin through a bushed mortise slot at the front. Both bushings are wool, wool swells when it takes on moisture, and once the swollen cloth grips harder than the key's own return weight, the key stops where you left it. Yamaha's care page says it outright: too much humidity gives you dull hammer action, unclear tones and sticking keys.

The note sounded normally, the key lifts with a fingernail but feels gritty, and two or three keys nearby are slow. Fine in February and stuck in July is what I bet on in a Nashville August. Quality Piano Tuning Services lists easing key centers at $55 and a full set of new bushings at $490 on a grand. If those keys have dragged for years through both seasons on a pre-1970 piano, suspect corroded key pins, which is a technician's call.

3. The keyslip crowding the key fronts

The keyslip is the strip of wood across the front of the keyboard that hides the key fronts, and uprights and grands both have one. Swollen wood, or a key block knocked loose in a move, lets it crowd back and pinch. Howard Piano Industries gives the owner test: pull back just a little on the keyslip itself, and if the key comes up, the slip is too close. Expect a run of keys in one area. Shimming it runs about $75 an hour on the published rate at Willey Piano Tuning in Renton, Washington, usually absorbed into a tuning.

4. The jack won't reset under the hammer butt or the knuckle ($30)

The jack is the L-shaped part on the wippen that pushes the hammer and then escapes. On an upright the jack spring has to return it under the hammer butt, and on a grand under the knuckle. Three things stop that: a jack flange center pin binding in its bushing, a broken jack spring, or a capstan screwed so high there's no lost motion left. The tell is intermittent: you lift the key, it plays correctly once, it sticks again. Quality Piano Tuning Services lists a jack at $30 and a spring loop at $30, plus labor. All three of those fixes need the action out of the piano.

5. Verdigris in the center pin bushings

Every pivot in the action is a nickel-silver center pin turning in a wool bushing, and two things seize it: humidity, and verdigris, a green corrosion that forms in the felt of mid-century instruments. Once the wippen or hammer hangs up partway, the weight that bears down through the capstan is gone and nothing returns your key. Lift the lid and look at the hammer line: a hammer sitting partway toward the string while its neighbors restRestA symbol indicating silence for a specified duration.The Savvy Take: Music is painted on a canvas of silence. The rests are as important as the notes. Don’t rush through them! A sudden silence (Grand Pause) is often the loudest moment in the piece.View in glossary → level puts the hang-up in the action, not in the key. Repinning a verdigrised flange only holds a while, because the verdigris stays in the felt. Replacing the affected parts outright means a full grand action rebuild, and Concord Piano publishes $20,000 for one covering all action, damper action, trapwork and pedalPedalA device on the piano operated by the feet. The right pedal (Damper/Sustain) lifts all dampers, allowing strings to vibrate freely. The left (Una Corda) softens the tone. The middle (Sostenuto) sustains only selected notes.The Savvy Take: Foot technique is as important as finger technique. Don’t just stomp it down. “Flutter pedaling” (rapid, shallow movements) can clear out the mud while keeping the sound warm. Pedal with your ears, not your foot.View in glossary → parts.

6. A crumbled drop-lifter elbow (spinets, 1940s into the 1960s)

Spinets use a drop action below the keys. A lifter wire runs from the back of the key to a small elbow on the wippen, and those elbows were molded in bakelite, which crumbles and snaps into pieces over decades. In Tune Piano Supply describes the symptom: the key stays depressed, the joint has broken, and the hammer never reaches the string. Confirm you have a spinet, the shortest vertical at roughly 36 to 40 inches, then press the key. It drops with no resistance and sits there, silent. Elbows cost $8.75 for a set of 12 at In Tune Piano Supply, $5.99 apiece, so the bill is labor, and a full set of 88 is where an honest technician asks whether the piano is worth it.

7. A key broken at the balance rail mortise

The key is one piece of wood with a hole bored at the balance rail, the weakest cross-section on the part. Howard's diagnostic list names it: the front moves independently of the back. You feel a soft dead drop and no sound. It follows an event, a slammed fallboard, something heavy set on the keys, or a butter knife under the key front. Figure Willey Piano Tuning's roughly $75 an hour, on top of a service call: $125 at Willey to look at a piano without tuning it, $75 minimum per site visit at TX Pianos.

8. A broken hammer shank leaning on its neighbors ($40)

The hammer shank is the dowel between the hammer head and the flange on a grand, or the hammer butt on an upright. A broken shank by itself usually gives you a silent note with a key that returns fine. Yours stays down only when the freed head falls forward and wedges against the strings or its neighbors. Look for a hammer at a wrong angle, or a head loose in the piano's bottom, and stop playing that note. Quality Piano Tuning Services lists a shank at $40 plus labor, or $35 to repair the one that's there.

What NOT To Do (The WD-40 Section)

No WD-40, no silicone, nothing from the garage. It works for about a week, which is why owners keep doing it. AAA Piano documented an upright where WD-40 "left an oily residue that attracted dirt and dust and caused the flange felt to harden onto the center pins." The action stopped working and sat dead for close to three decades.

No prying with a screwdriver or a butter knife. The leverage lands right at the balance rail hole, which is where keys break. You'd convert a $55 easing into a broken key plus a chipped keytop.

No pounding the note to knock it loose. A wedged coin gets driven deeper, and a loose hammer head gets driven into the string plane.

Don't pull the action out to look. Pressing keys down while sliding a grand action out can snap hammer heads off. On an upright, the key stop rail and fallboard come off before any key does.

No alcohol and no Windex. Liquid runs down the keytop sides into the bushings, and a sugary spill dries into glue.

42 percent, and no mason jars

If two or three neighbors went sluggish over a humid week, the fix is in the room. Yamaha's care page publishes a target of 40 to 45 percent relative humidity, and a pan of water in the piano regulates none of it. Get there with room equipment, a humidifier in January and a dehumidifier in July, or with an installed system, and buy a hygrometer so you know which one you need. That same swingSwingA rhythmic feel in which paired eighth notes are played unevenly — long-short, leaning toward a triplet subdivision — rather than straight.The Savvy Take: Don't do the math; do the listening. Swing is a feel with a dial, not a formula — lock your comping into a great ride-cymbal pattern (or a Basie record) and your hands will find the ratio your ears already know.View in glossary → is why your piano won't hold a tuning, and winter does its own damage.

The Savvy Verdict: what $125 buys you

Four of these eight causes require pulling the action out of the piano, which puts most of this list past anything an owner can reach from the bench. Willey Piano Tuning in Renton WA lists $125 for an evaluation, and $240 for a tuning that includes up to a half hour of small repairs, sticky keys named on the list. That's the cheapest way to buy this if you were due for a tuning anyway. Every part named above is in the glossary, and while the action is out, ask about voicing too.

Prices checked August 2026.

Take the flashlight to both sides of that key tonight. If nothing's down there, leave the key alone until the appointment. The $55 easing is still on the table this week, and it stops being on the table the moment somebody pries.