Missing strings can damage the hammers in a grand piano.
Piano strings are under many pounds of pressure, and they occasionally break. This can occur due to wear, poor tuning techniques, and extreme changes in temperature and humidity. While you'll bring in a professional to tune the piano eventually, you can replace the strings yourself to save time and money. The main trick is bringing up the tuning of the new string gently so the pressure increases gradually.
Instructions
1. Prop the piano lid open and remove any score holder from the front of the piano. Extract the broken strings from the piano. If necessary, put the piano tuning key (kind of like a vertical wrench) on the metal pole at the front of the piano the string is attached to, and turn it counter-clockwise until you can pull out the string. Dispose of broken strings since they cannot be repaired.
2. Check the packaging on new strings to make sure they're the correct note and octave. The strings in a grand piano go steadily from large ones at the low end to thin ones at the high end. If your string is a different size than the ones around, it it's the wrong string.
3. Hook the looped end of the string over the empty hook near the back of the piano. Gently stretch out the string to the front and thread the other end through the hole in the tuning spool. Put the tuning key on again and turn until the string starts to tighten. Keep turning until the string has tension but is still lower than the strings around it.
4. Replace any other strings as needed, then return to the first string. Tune it higher again and test it against the notes above and below it. Work gradually until it's the appropriate pitch. Repeat with other new strings.
