The problem du jour: discs.
- By Mike Lewis

Scenario 1: Imagine that you have to play an important gig and your 4th octave F# disc has broken off one of its disc pins.
Scenario 2: Imagine that you are touching up the intonation on your harp between regulations and, to try to get the pitch down on the third octave C#, you want to adjust a disc.
Scenario 3: Imagine that your third octave C natural is buzzing and, as you play, you can see the string lifting off of the lower disc pin.
What do you do? Start playing the "Where's My Technician?" blues? No!! None of these disc-related problems are difficult to solve. In fact, discs are one of the few things that every harpist needs to know how to change. So grab your screwdriver and let's go change a disc or two. First let's make a side-trip to...

Let's clear up the jargon issue for those who don't know the terminology associated with discs, or for those who do know and the "I'm-calling-your-this-my-that" issue is stopping us from understanding one another.
Discs are the small, round and oblong pieces of metal that bend the string when you move the pedals. (see figure 1).

Disc pins are the pieces of tapered metal or straight plastic that stand 90 degrees perpendicular to the body of the disc. The disc set screw is the screw that stops the disc from coming free. The spindle is the axle-like component inside your action that rotates when you move the pedals. The disc is screwed onto the spindle. If you think of your action as a brass sandwich, the front action plate is the top slice of bread, the spindles are the meatballs and the back action plate is the bottom slice of bread. (The back action plate is illustrated and will be a topic of future discussions, but for now think of it as forbidden fruit.) There are three different types of string nuts (none of which are edible): Stationary string nuts (see figure 2), which are called stationary for one very simple reason (you get to guess!). You generally find them in the bass range of the harp. They are mounted directly on the front action plate.
Adjustable string nuts (see figure 3), which, unlike the stationary string nuts, can be moved. You generally find them in the harp's mid-range. They are mounted on a brass bracket that allows for the adjustment of position and is held in place by the adjustable set screws.

Overlapping string nuts (see figure 4),which are also moveable. As their name suggests, they overlap the discs in the treble end of the harp. They are mounted on a piece of bent brass, and are held in position by adjustable set screws.
The last stop in our tour of the Jargon Café is the ever-controversial grip table (see figure 5). I say controversial because one harpist's "grip" is another harpist's "buzz." Figure 5 is my take on what constitutes "standard issue" grip.

LET'S BLOW THIS JOINT AND GET DOWN TO BUSINESS A review of the three reasons why you would need to know how to change or adjust a disc: 1. The disc is broken. 2. Bad intonation. 3. Improper grip is causing string buzzing. Step 1: Get That String Out Of The Way (see figure 6).

No matter which of these scenarios applies to you, you need to get the string out of the way first. Put all your pedals into flat and then loosen the tension of the string by lowering the pitch. Remove the string from the string nut.
Step 2: Do one of the following, depending on your reason for working on the disc. If you have a broken disc pin: 1. Take your screwdriver and turn the disc set screw counter-clockwise. (For you younger readers who only know digital watches or clocks, please ask your parents about this.) Make sure that the screwdriver and the slot in the set screw are a good, tight fit (see figure 7), because the disc is jammed against the set screw and you will have to use some force to get this set screw to turn. (Very important: "some force" is not "a lot of force.")

2. To remove the disc once you have the disc set screw out, you need to grab hold of the unbroken disc pin and turn clockwise. The discs, by the way, are the only parts on the harp that screw on tight counter-clockwise (everything else screws on tight clockwise). If you have bad intonation or bad grip: 1. Stick the blade of the screwdriver (carefully!) in between the disc pins and turn counter-clockwise (see figure 8). Doing so moves the disc away from the disc set screw and makes removal of the disc set screw much easier.

2. Take your screwdriver and remove the disc set screw by turning it counter-clockwise. 3. Grab hold of the disc pins and turn clockwise to remove the disc. Step 3: Putting on a new disc. (If you only have bad grip skip step 3 and jump to step 4.) 1. Look at figure 1 to see how the disc is parallel to the front action plate. Then, on your harp, align the hole on the back of the disc with the spindle and turn counter-clockwise. Do not get frustrated if it takes several tries in order to get the threads to catch. 2. Once the disc is on, turn it counter-clockwise until it won't move any more. 3. Turn the disc one turn clockwise to move it away from the front action plate. 4. Put the disc set screw into the hole in the middle of the disk and turn clockwise until it gently touches the disc. You are now ready to set the grip. Step 4: Setting the Proper Grip. (Even if improper grip wasn't the original reason for changing your disc, you need to set the grip now that you have changed the disc.) 1. Grab your screwdriver with one hand and the disc pins with the other. Loosen the disc set screw by turning it counter-clockwise. 2. Look at the angle of the disc pins. 3. Match the angle of the disc pins on the disc you just changed to the angle of the disc pins on the discs around it. For example, if you are replacing B natural, look at C natural or A natural. The important point here is that if you are working with a disc with two disc pins, do not look at a disc with one disc pin for reference. 4. Tighten the disc screw. 5. Replace the string onto the string nut. 6. To check your work, gently move the corresponding pedal so that the string is gripped by the disc pins. "Gently" is important, because if you have too much grip and the pedal is not into its full position yet, you can ruin your gut string. Too little grip and you will get a string buzz. 7. In order to fine tune grip (whether you have too much or too little grip), you will need to remove the string from the string nut and loosen the disc and disc set screw (see figures 6, 7 and 8). Too much grip? Turn the loosened disc clockwise and tighten the disc set screw. Too little grip? Turn the loosened disc counter-clockwise and tighten the disc set screw. 8. Check again to see if you've established the proper amount of grip and keep repeating until the grip is set properly. How can you tell if you have proper grip? Use figure 5 to get you in the ballpark and use your ear for final product. Don't get frustrated if it takes longer than you expected to change a disc and set the proper grip. If you mess up, practice your "I-hit-my-thumb-with-a-hammer" vocabulary and try again. It's what I do. THE HARP COLUMN May/June 1996