This guide breaks down the essential parts of a piano you need to know to judge condition, request repairs, or improve playability — focusing on the exterior, action, strings, soundboard, and the small hardware that changes tone and feel.
Labelled field guide to the piano exterior — case, lid, fallboard and visible hardware
The music desk or music rack holds scores; check its hinges and adjustable stops for stability and straightness.
The fallboard (key cover) protects keys and often carries cosmetic damage; it should close smoothly without rocking or binding.
The lid on a grand uses a lid prop or lid stick; inspect the prop notch and hinges for wear that affects safe propping.
The rim and case show maker styling and veneer condition; look for separated seams, loose trim, and repairs that change resale value.
Legs, the lyre (pedal housing), and casters determine mobility and where you can place the instrument in a room; stiff casters or missing lyre screws create moving hazards.
Locate serial numbers on the plate or soundboard, and find the manufacturer plate usually near the tuning pins; photograph both for records and insurance.
Visible wear that affects valuation includes deep veneer cracks, water stains, and loose brass trim — these are repair items that reduce asking price.
Exterior parts that matter for sound and access
On grands, opening the lid changes projection dramatically; a fully open lid sends more direct sound to the audience, while a closed lid softens projection and blends overtones.
Upright lids and top boards alter tone less but affect player access for tuning and repairs; check that hinges, screws, and access panels open without stripping or sagging.
Inspect for cosmetic versus structural damage: superficial chips and scuffs are cosmetic; cracked ribs, split rim sections, and delaminated soundboards are structural and costly to fix.
Inside the cabinet — the keyboard and action anatomy that turns fingers into sound
The visible keyboard parts include keytops, keybed, keyframe, and balance rail; worn keytops or loose key bushings cause wobble and uneven touch.
Front and back escapements affect how a key releases the hammer; check that escapement surfaces are even and that key dip is consistent across the set.
Key bushings hold each key on the guide pins; compressed or missing bushings produce side play and inconsistent feel.
Action assemblies: mapping what moves when you play
The wippen transfers key motion upward; the jack (sticker) pushes the hammer but must pivot cleanly for reliable escapement.
The repetition lever and repetition spring allow fast retriggering on grands; check spring tension for quick response and minimal sticking.
Backchecks catch hammers during rapid play and prevent bounce; worn checks cause double striking or muffled repetition.
The hammer rail secures hammer shanks; loose rail bolts create rattles and misalignments that alter strike points on strings.
Action subcomponents a pianist should know
Hammer shank connects the key mechanism to the hammer head and must be straight and securely glued to avoid mis-strikes.
Hammer head felt density and shape directly shape attack and brightness; compacted or grooved heads ring harsh or thin.
Flange houses the pivot point of shanks; worn flanges produce wobble and flutter in the action.
Capstans and the capstan screw adjust key height and let you set initial key position; improper capstan setup changes key dip and regulation.
During regulation, technicians set let-off (escapement distance), drop (how far the hammer falls after let-off), and travel (key movement), which together determine touch weight and repeatability.
Strings, cast-iron plate (harp) and soundboard — the physics of tone production
The cast-iron plate supports all string tension; plate numbers and model IDs are stamped and help confirm manufacture date and model for valuation.
Bass strings are wound (steel core wrapped with copper) and treble strings are plain steel; differences in material and winding affect sustain and inharmonicity.
Strings anchor at hitch pins, pass over the bridge, and couple energy into the soundboard; bridges must seat cleanly on the soundboard for accurate transmission of vibration.
The soundboard — usually quarter-sawn spruce — has ribs and a crown; the crown (slight arch) provides projection and dynamic range; flat or cracked soundboards lose responsiveness.
Tuning and pitch hardware
Tuning pins sit in the pinblock (wrest plank) and hold string tension; a tight pinblock means stable tuning, while loose pins cause rapid detuning.
Pinblocks are typically multi-laminated maple; separation between laminations signals a major repair or replacement need.
The capo d’astro bar on many grands defines speaking length for treble strings; damaged bars or loose agraffes change pitch and tonal balance.
Duplex scale or additional non-speaking string segments can add shimmer or sympathetic resonance; missing or altered duplex parts shift sustain and color.
Hammers, felts and voicing — shaping tone, attack and sustain
Hammer cores are wooden and covered with layered felt; felt density and quality set initial brightness and dynamic control across registers.
Felts compress with use; heavy grooves at strike points make tone harsh and reduce dynamic range — the standard fix is reshaping or full replacement.
Voicing includes needling to soften, filing to reshape, and lacquer to harden; each method targets a specific tonal correction, and over-voicing causes lifeless sound.
Alignment and spacing of hammers affect evenness; a shifted hammer strikes off-center on the string set and produces uneven tone or buzzing.
Dampers, sustain mechanics and the pedals — controlling decay and color
Dampers use felt to mute strings; check that damper felts contact strings evenly across registers and return promptly after release.
The sustain (damper) pedal lifts all dampers and lengthens decay; the soft (una corda) pedal shifts action or bridge contact to soften tone; the sostenuto pedal holds selected dampers while others function normally.
Half-pedaling controls partial damper lift and lets you shape sustain; accurate half-pedaling depends on properly adjusted pedal travel and mechanism linkage.
Pedal linkages, rods, and the pedal lyre should move freely; squeaks, sluggish return, or lost motion usually indicate worn bushings or missing lubrication.
Structural backbone — rim, braces, back posts, pinblock and fasteners that hold it together
Rims are either solid wood or laminated strips glued around the case; laminated rims resist warping better and are commonly used on modern grands.
Back posts and internal braces support string tension; any crack or separation in these elements affects tuning stability and may require major repair.
Pinblock durability depends on tight lamination and proper glue; a delaminated pinblock cannot hold tuning and often needs replacement.
Loose key bolts, hitch bolts, and screws produce buzzing and shifting; systematically tighten and record torque values rather than guessing.
Grand piano vs upright mechanics — why orientation changes parts and performance
Grand actions are horizontal with gravity-assisted return and faster repetition; upright actions are vertical and use springs to aid repetition, which changes response and feel.
Grands generally have longer strings and more exposed soundboards, yielding greater projection and tonal richness; uprights trade space for compactness and shorter string length.
Pedal mechanisms differ: grands use direct linkage to the action and soundboard; uprights route pedal motion to a pedal rod and lyre assembly that can introduce play or noise.
Transport and room placement matter: grands require more clearance for lid opening and moving, while uprights fit tighter spaces but may suffer if placed against a cold or damp wall.
Materials and modern variations — from ivory keys to carbon fiber actions
Keytop materials evolved from ivory to celluloid and acrylic, then to durable phenolic and modern plastics; verify provenance for instruments with historic ivory.
Hammer felts vary in wool density and sewing method; premium felts last longer and voice more predictably than lower-grade alternatives.
Modern innovations include composite keyframes and carbon fiber action parts that resist humidity and reduce long-term maintenance while preserving performance.
Factory voicing differs between brands; two pianos with identical specs can feel and sound different because of voicing choices and hammer finish.
Maintenance, tuning and common part-specific repairs every owner should expect
Recommended routine: tune at least twice the first year for a new or moved piano, then quarterly or biannually for settled instruments; regulate action annually for regular players.
Common repairs: broken strings, replacing worn hammer felts, re-bushing keys, replacing pinblocks, and fixing cracked soundboards or glued seams.
DIY checks you can do safely: tighten visible loose screws, check caster operation, and visually inspect for gaps or loose glue joints; never force internal adjustments.
Call a qualified piano technician for tuning, voicing, pinblock or soundboard work, and any repair that requires partial disassembly of the action or removal of the plate.
How individual parts influence playability and sound — practical tips for pianists
Squeaky or sticky action usually points to flange wear, dry bushes, or misaligned shanks — highlight exact keys to the technician for targeted fixes.
A bright, brittle tone often signals hard or compacted hammer felt; request softening by needling or replacing hammers in severe cases.
Heavier action gives more power but requires stronger technique; if you need more speed, ask for lighter touch weighting or adjusted repetition springs on uprights.
For repertoire with long singing lines, request sustain pedal adjustments and careful voicing in the treble to improve legato and color.
What to inspect when buying, selling or insuring — part-focused checklist
Essential checks: stable tuning (pinblock and plate), clear soundboard with no open cracks, even hammer wear, full key travel, and responsive pedals.
Collect documentation: serial numbers, plate cast markings, maintenance records, and receipts for replaced parts like pinblocks or soundboards.
Red flags include missing parts, extensive repairs to the pinblock or soundboard, mismatched replacement parts that alter original sound, and warped rims or loose braces.
Quick-reference glossary of critical piano parts and jargon every pianist should know
Action — the combined mechanism converting key motion into hammer strike; also called the key action.
Jack (sticker) — the small lever that propels the hammer toward the string and disengages at let-off.
Escapement / Let-off — the point where the jack releases the hammer so it can strike freely; critical for repetition control.
Agraffe — a small brass guide for string alignment near the tuning pin end on some grands; keeps string spacing precise.
Capo d’astro — a bar that defines speaking length for treble strings on many grands, affecting harmonic balance.
Duplex scale — non-speaking string lengths that vibrate sympathetically and add color and sustain.
Pinblock / Wrest plank — the laminated wood block that holds tuning pins; its health determines tuning stability.
Backcheck — the device that stops a hammer after it rebounds, allowing rapid repetition; often a leather or felt catch.
Harp / Plate — the cast-iron frame carrying string tension; stamped numbers and maker marks on the plate help verify age and model.
Fallboard — the key cover that protects keytops when the piano is not in use.
Use this glossary during technician conversations, condition reports, and insurance forms to describe problems precisely and avoid misunderstandings.
