Piano Technician Academy’s Piano Tuning Course

September 1, 2025

Book Notes

When I read a book I have the habit of highlighting certain passages I find interesting or useful. After I finish the book I’ll type up those passages and put them into a note on my phone. I’ll keep them to comb through every so often so that I remember what that certain book was about. That’s what these are. So if I ever end up lending you a book, these are the sections that I’ve highlighted in that book. Enjoy!

TO DO

• Make blank pictures of the action, then practice filling in the blanks
• On an upright, try to adjust the position the hammer hits the strings by loosening the screw and moving the hammer, then tightening it
• On an upright adjust the lost motion so that when using the measurer, the key barely lets off when fully depressed with a bit of pressure. Felt may need to be added to the top of the let-off switch to achieve this
• On an upright, adjust the backchecks (lesson 5)
• Replace the pin in one of my hammers.
• Understand the theory of Aural tuning
  1. The order of operations for the process of oral tuning
  2. temperament strips and their function
  3. Partial/overtones and be familiar with at least the first 8 partials
  4. The concept of harmony and why it’s present in string scales
  5. Beats and why they occur
  6. Identify major third fourth fifths and octaves. witch intervals are narrow or wide, and by how much

Full Service Tasks

• Tighten all screws
  • Whippen flange screws
  • Hammer flange screws
• Polish & lubricate front and balance rail pins
• Check the bridle straps. Is the jack 2mm from the bottom of the hammer butt when action is removed? Is the bridle wire bent such that it doesn’t contact the backcheck or action next to it? Make sure they aren’t pulled too far forward so that the jack can’t reset (Especially noticable when the soft pedal is played – the bridle strap might lift the whippen) when putting the action back in. these two items could be after aligning the hammers if I’m finding it’s easy enough on an upright. Spinet is not easy
• Center the backchecks with a wire bending tool
• Square the keys by tapping the balance rail pins with a flathead screwdriver and hammer.
• Space the keys by using the forked key spacing tool and placing it below the front rail cushion, then twisting left or right to get the proper space
• Align the hammers to hit the middle of the strings by loosening the hammer flange screw, adjusting the hammer, then tightening the screw. If not able to move the hammer enough, remove it and then add traveling tape. If hammer heads are bent, use a heat gun to heat up the hammer shank, and twist the hammer head in the direction you want it to go while doing so. Then continue to heat the shank until it becomes almost malleable. At this point position it whenever you need. (lesson 4)
• Center the capstan with a wire bending tool
• Adjust the lost motion by moving the cpastan up or down so that the back check moves slightly before the catcher when the key is lightly pressed.
• Level the keys
• Adjust the let off screw so that the hammer lets off 2mm before hitting the string
• Check that all dampers let off at the same time when pedal is pressed. ADjust dampers as needed.

Troubleshooting

Clicking noises

• Check the bridle straps. Is the jack 2mm from the bottom of the hammer butt when action is removed? Is the bridle wire bent such that it doesn’t contact the backcheck or action next to it?

Sticky/Sluggish return

• Check the balance rail bushings. Do they allow the key to wobble more than 2mm but less than 5mm? If not ease the keys and create the proper space. If the key is still sticky, check the balance rail hole. If needing to make it bigger, keep the key barely on the pin and push the key back and forth to widen this space. (lesson 4)
• Bridle wire might be pulled too far back, not allowing the jack to be reset

Damper issues

• Bend damper wire to adjust placement of dampers
• Bend the damper spoon so the damper lifts when the hammer is a third to half the distance to the strings. Bend the spoon forward toward the strings to make the damper lift sooner in the keystroke and bend it back to make it lift later.

Replacing Hammer Pin

• Remove hammer, do swing test. Looking for 5-8 swings to be ideal
•  If the swing test showed that the hammer flange was too loose, you’ll need to select the pin one size up from the one that was in the flange. If too tight, you’ll use the same-sized pin as the one that was in the flange.
• A good rule of thumb is that the correct-sized pin is the size one up from what you can push through the birdseye with your finger. For example, if you can push a size 20 pin through the birdseye with your finger but you can’t push a size 20.5 pin through, use the size 20.5 pin. 

• When insatlling a new pin make sure the flange isn’t upside down. The drop screw needs to be on the top.
• If it swings fewer than five times, you’ll need to ream and burnish the felt bushings. Insert the reamer into the felt bushings and run them through the rough section of the reamer a couple of times. Move the bushings to the smooth section of the tool and burnish the felt by quickly moving the tool back and forth.
• If needing to replace the flange bushing, Renner USA sells a flange bushing cloth with a water-activated glue inside the cloth. Simply pull the cloth through and dab it with some water.

Replacing a Hammer Shank

• Use your cutting pliers to cut the old shank as close to the hammer butt and other part as possible. Then sand until flat
• Drill a new hole in the head, and other part.
• Install other part on piano, then Insert a new shank. Make mark, cut shank to right head and then glue evertyhing together. Make a little valley on the end of the shank to let glue escape

Replacing a String

• Loosen pins (About 5 quarter turns)
• Measure gauge of wire with a micrometer. 
• Get new wire, Use coiling tool. Insert new wire and have it just barely sticking out of the pin on the coiling tool. Put 2.5 turns into a coil. Pry out that wire from the dummy pin, and insert it onto the pin on the piano. Squeeze it into place with pilers, twist a bit with tuning hammer, then squeeze it again to keep it in place.
• String the string threw the bridge pins, and around the hitch pin. Do it as tight as possible (maybe wrap around more), it makes it easier. Cut the string, give yourself more than you generally need.
• Run the string under the cable bar, through the bridge pins, and place the index finger above the pin you’ll put it on, then use the 4 finger trick to determine correct amount where to cut the string to. Use the coiling tool again, and repeat the process to put the string onto the actual pin on the piano.
• Bring the string up to tightness. 1 half turn with a coil lifter underneath the string, then after squeeze it with a Beckett pilers. Repeat this process 3ish times.
• Before it’s totally tight, align the string to the prior hammer grooves. Use a coil lifter tool to place it onto the aliquouh when the string is tight enough
• you want the string to cover about the bottom half of the circle of where the string is inserted into the pin. To high? Tap it down with a hammer and brass. Too low? Loosen while using a coil lifter, then tighten. Then squeeze Becketts again 1 last time.
• Tune the string. Then seat the string with a gentle tap of the hammer and bass rod on the bridge. Then tune again cause it probably got knocked out of tune.

Replacing a Bass string

• Count the tuning pins, starting from the bottom, until you arrive at the tuning pin with the broken string. This is the string number. For other brands, you may also need to supply the thickness of the string and the distance from the hitch pin to the bridge pins and agraffe.
• In the bass, there is a piece of felt that runs in and out of the back section of the strings (called the back duplex). The result is a pattern of one bass string on top of the felt, then the next string below the felt, and so on. Ensure that your string matches the pattern. If your string needs to be on top, simply place the bass string onto the hitch pin. If your string needs to be on the bottom, you will need to slide it underneath the felt before placing it on the hitch pin.
• Remove the bass string from the hitch pin and use vice grips to grab the end of the string and rotate it in the direction of the copper winding. For example, if the string was wound counterclockwise, twist the bass string in a counterclockwise direction once. Then, return the hitch pin loop to the hitch pin.

Creating a Hitch pin loop

• Grab the string with your round nose pliers and rotate it until you have a nice, round loop in the wire, with the tail pointing up. The tail should be on the side closer to the end of the pliers.
• Notice that the thickness of the round nose pliers is tapered, meaning that the end is thinner, and it gets thicker as you approach the handle. Grab the string at a point where the loop will be wide enough to fit around the hitch pin, but not too much wider than that. Pull the long end of the string toward you to put a small bend in the wire so that the long end of the string comes straight down and the tail slopes down.
• Use a twisting tool to twist and braid the wire around itself.

Splicing a string

• Reference Lesson 9 for method

On Auntie Shelley’s piano, some keys click and some keys stick

Possible needed tools

• pin punch
• Vaccuum
• profelt
• Business cards to prop up the balance rail all at once
• Replacement bridle straps. Cork, clip, & plain
• tacky glue
• Xacto knife
• Traveling tape
• Look into a tool to bend the capstans on a spinet if I’m running into lots of cpstans being off-center. They’re thicker and I don’t have a tool that will work for it currently
• felt
• Replacement strings
• Hitch pin loop twister

Notes

Uprights

• 36″ – 40″ Spinet
• 40″ – 43″ Console
• 44″ – 48″ Studio
• 49″ + Full Upright

Grands

• < 5’8″ Baby Grand
• 5’8″ – 6′ Parlor Grand
• 6′ – 8′ 10″ Grand
• > 8′ 10″ Concert Grand

Lesson 1

• Just like a house, a piano has a frame that the rest of the piano is built on. On a grand piano, this frame is referred to as a skeleton. 
• The piano soundboard is typically made of spruce (Light weight, uniform grain structure, strength). The blank is usually about 3/8″ thick
• The ribs are typically made of sugar pine
• The bridge is typically made of maple or beech (Durability, can withstand constant pressure from strings)
• ribs go against the grain of the soundboard
• The soundboard has ribs that it doesn’t change shape overtime the shape is critical to the sound and the tone of the piano
• The convex shape of the soundboard is known as a crown
• Piano makres usually aim for 1/8″ in crown
• To get the convex shape of the soundboard the ribs have a curve to them and when the soundboard is glued to the ribs you produce this convex bowl
• 4 parts that make up the piano: the action, the tuning, the voicing, and the belly

Lesson 2

• The actual sound comes from the soundboard vibrating. The strings vibrate and their vibration is transfered through the the bridge (What connects the strings to the soundboard) to the soundboard.
• Placing the brdiges in the exact perfect spot on the soundboard is critical to get the best tonal quality. You woouldn’t hit a drum on the side, you hit it in the middle to get the best sound.
• There is a black graphite paint on the bridge, which allows for the strings to move freely when being tuned.
• The bridge pins are copper-plated steel pins.
• The bridges are higher than the plate so that the string produces a cxownward pressure on the plate, called down bearing.
• Strings are made from high-carbon steel wire (Immense strength, elasticity, ability to withstand tension)
• The thickness of the strings is referred to as the gauge of strings
• The bass strings are steel, wound with copper
• As the piano gets shorter, you need more wound strings. In a concert grand, bass strings aren’t as thick.

Lesson 3

• Fortissmo = loud
• Pianimissio = quiet
• On a spinet, if it has  ametal sticker (I think capstan?) that attahes to the end of the key stick with a rubber grommet, this is called a standard action.
• A thayer action has a seperate mechanism connected to the action that keeps the stickers in place. (My piano)
• Grands have a repition lever, which allows keys to be played again without fully releasing them.
• The pedals in a grand piano are reffered to as the Lyre
• When pedals are depressed, they move rods upwards. This is called trapwork
• Grand pedals
  • Left: Una Cora. Or soft pedal. Shifts the entire keyboard to the right so that the hammers hit 2 strings instead of 3. Creates a quiter tone.
  • Middle: Sostenuto. When a note is played and this pedal is pressed, it grabs the damper assembly and holds on to a played note’s damper so it can ring while others are played with the damper still on. On cheaper baby grands it only lifts the damper on the bass notes
  • Right: Sustain. Lifts all the dampers.
• Upright pedals
  • Left: The soft pedal. Moves the hammers closer to the strings to make notes quiter.
  • Middle: Does one of the 3
    • Lifts the bass dampers
    • Is the practice pedal. Drops a piece of felt between the strings and the hammer to soften the blow
    • Is the sostenuto.
  • Right: Sustain.

Lesson 4

• The process of maximizing the action parts potential is called regulation
• Action servcing steps
  • Tighten all screws
  • If the pins are rusted, use a metal polisher (Flitz) and steel wool to clean them off.
  • Vaccum, compressed air, then spray lubricant on keyframe pins. (McLube 1725)
• If the back rail felt is not level, the keys will not be level.
• On the key the front hole is called the front rail bushing, the middle hole is the balance rail bushing, and the hole on the bottom in the middle is called the balance rail hole
• If keys are too tight the piano will feel sticky or sluggish, if they are too loose the keys might click or feel sloppy and hit against each other
• Easing keys is opening up those bushings with a key easing pliers to make sure they wobble ever so slightly left and right. There should be just a small amount of play. Not so much that the key displaces from it’s original spot though. You can also use the pin to push back and forth against the bushings so that the key drops smoothly onto the pin
• If you over-eased and the keys are too sloppy, you’re need to soak the bushings with profelt and leave them overnight, they will have swelled the next day and you can re-ease them.
• With the bridle strap, you can bend the wire it’s attached to to create more/less space between the hammer butt and the jack. There should be just a minimal amount of space between the two, just so that they’re not touching. Make sure these wires are not bent left/right so much that they are touching the back check wire on the key next to it. This can create a clicking noise.
• On replacing bridle wires
  • 3 options – standard, cork, or clip on.
  • Clip on are easiest but not recommended if doing lots of replacements
  • Cork is good, you’ll need several different sizes, and the need to glue them (With tacky glue) in when placing them. Once glue is dry then attache the bridle wire. Standard (Just the wire without a cork) is the best option for long term. Have to cut the wire the the proper lenght and re-glue them to the baclk of the back check catcher.
• It’s usually easiest to install the damper pedal rod before putting tightening the action bracket bolts
• To square the key, use a hammer and chisel to tap on the balance rail pin. use a level of sorts to check for unsquared keys
• To space the keys, use the spacing tool. Lift up the key, place the tool below the rest cushion, the twist (Or maybe just move left to right) the tool slightly to adjust the spacing
• If you have loose key bushings, you won’t be able to square or space keys without replacing the key bushing first.
• Space 3 & center things on the action:
  • Make sure the hammer is centered on the strings. loosen the hammer screw so it can move a bit, center it on the dstrings, then tighten the screw
    • If you can’t move the hammer enough, use hammer traveling tape.
    • If a hammer head is tilted, you’ll need to use a heat gun to heat up the shank until it becomes malleable. Move it into place and let it dry.
  • The backcheck. Make sure it is centered. Use a wire bending tool to do so.
    • If working on an old pieno, it may not be a good idea to move these to drastically unless you want to replace the felts.
  • The Capstan. Make sure it is centered. Use a wire bending tool to do so.

Lesson 5

• The main goal of regulating the piano is to maximize the power, control, repetition, and consistency.
• Aftertouch is the amount that the jack escapes from the butt (or knuckle, on grands) when the key is fully depressed. Camn also think of it as the amount that the key travels after the hammer has achieved let off.
• Play the key very slowly but don’t allow the hammer to strike the string. If your action is properly regulated, you will feel a small bump in the key as the jack is tripped out, and the key will go down ideally 1.5mm beyond this point. That final distance the key travels after letting off is our aftertouch.
• If there is too much aftertouch, we will not have as much control, power, or repetition. If there is too little aftertouch, the hammer will likely double strike and there will be a mushy, incomplete feeling in the action.
• If the jack trips out from the butt when the hammer is farther away from the string (and vice versa), the note will have more aftertouch.
• Blow distance is the amount of space the hammer travels from rest to impacting the strings. If the space is decreased (meaning the hammer is closer to the string at rest), there will be more aftertouch.
• Key dip is the distance the key travels from its rest position to being fully depressed. We can adjust that distance by adding or removing paper punchings below the front rail felt cushion. If the distance the key travels is increased or decreased, the aftertouch will also increase or decrease.
• Lost motion is the space between the jack and the hammer butt. There should be a small amount of space but over time this gets bigger and we don’t want that.
  • To set this properly, Use a capstan wrench to adjust the capstan screw so that the backcheck moves just slightly before the catcher.
• We set the lost motion, then we set the blow distance, then we set the lost motion again. If we don’t adjust the lost motion first, the excessive lost motion can cause the keys to dip down and give use a false sense of key level.
• A good height for keys is anywhere between 17 -22mm. This distance is from the top of the key slip to the underside of the keytop. If you set the height to 21 mm and the bottom of the lkey exceeds the key slip, you’ll need to move it down. The bottom of the key should not show. Similarly, if the height is set to 21 and there is no space between the key and upstop rail, you’ll need to adjust it down. You need to find the middle ground in which the key has room between the keytop and the fallboard, and looks good compared to the key slip.
• Always place punchings below the felt
• The sharps should be set to 13mm above the naturals
• To set the key height:
  • Load up the A0 key with punchings on the front rail cushion to the desired height.
  • Measure that height and use it as a baseline for the C8 key
  • Put a leveling stick across those keys
  • Check for too high keys by placing the leveling stick down several times and seeing if any keys move
    • Remove paper punchings on the balance rail under the high keys until they are level
  • Then add punchings to keys that are too low
  • Try tapping all the keys from the underside too see if they make a click sounds that signifies they are too low
  • Then do the same for the sharps. You might not be able to prop up the end sharps so instead you just need to rest the leveling stick vey lightly on the shraps or measure each on individually to 13mm above naturals height
• Steinway pianos have a crowned set of keys compared to perfectly straight
• Wood expands with a high moisture, and contracts when mositure is low
• To adjust the let-off, we turn the screw attached to the let-off button up or down. When we turn it up, we make the hammer let off closer to the strings, thus decreasing the total amount of aftertouch. Turning the screw down makes the let-off farther from the strings and increases the total amount of aftertouch.

Lesson 6

• The upright action is known as a single escapement mechanism, and as such, the design has some limitations when it comes to repetition.
• With the single escapement action, the key needs to be almost completely back in its rest position before the note can be struck again. However, the grand action remedies this issue by means of its double escapement design.
• NEVER press down on the keys while removing the action from a grand. You’ll snap the hammers off
• when lubricating the pins on the grand action also spray the sides and the front and the back so the keybed can slide easily

Lesson 10

• The A4 key is tuned to 440hz, all other kleys are tuned relative to that key.
• Once the pitch note is set, then build a temperment (Tune all the keys in an octave relative to that pitch note)
• Aural tuning is done with a temperment strip (to mute 2/3 of the strings). Once the un-muted note is tuned, the temperment strip is removed and the other 2 strings are tuned to match the in-tune one
• A group of two or three stings per note is called a unison
• If the tuning fork is heated (perhaps from being left in a hot car all day), then the pitch of the fork will be slightly lower than 440Hz; the opposite is true for extreme cold.
• Higher the Hz = higher the sound
• Partials are the fundamental frequency + the overtones
• Overtones are only the partials above the fundamental frequency
• Out of the 3 partials that make up a tone, the fundamental partial (lowest and biggest wave) is the one we usually most closely associate with the note.
• Over time, the 2 upper partials tend to get louder, and can overshadow the fundamental partial. That’s what makes an insurment bright, harsh, or tinny
• Lower notes have around 4-6 partials, higher notes have 8-12
• How to find the first 8 partials:

• For perfect partials, you would need a string exactly half the length of the previous string. But that would make the piano way too long if you scaled up. So string weight and size accounts for this. But that also means the partials will never be perfect multiples. This idea is referred to as inharmonicity.
• If two tones are perfect, they ring. If one is slightly off, we can head an audible beating sound. The further away the notes are, the faster the besting gets, until it just becomes an audible coarseness.
• Each interval has to be tuned either wide or narrow to create a proper temperment
  • Octaves – Throughout the piano, octaves are tuned wide of pure by roughly half a beat per second. Practically, this means that we tune the octave to sound pure and then widen it out just a hair until it has a slow roll in the tone without a distinct beating sound. Listen for 4:2 partial (Which means listening to the 4th partial of the bottom note of the interval, which also happens to be the 2nd partial of the top note)
  • Perfect 5ths – Spans 8 half steps. Should be narrow of pure. Should beat slighty faster than your octaves and slighty slower than your 4ths (3:2 coincident partial)
  • Perfect 4ths – 6 half steps. Should be wide of pure by one beat per second. (4:3 coincident partial)
  • Major 3rd – 5 half steps. Should be wide of pure, but increases in beats as you walk up the scale. (5:4 coincident partial)
• A coincident partial is like 4:2 or where the first number is the 4th partial from the bottom note, and the second is the 2nd partial from the top note

Lesson 11

• If you use a test blow in one of the strings drops down in pitch, you likely didn’t move the pin inside the pin block

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