Limitations of Music Box

Before reading this, we recommend visiting “The Mechanism of Music Box” to better understand how a music box works.

Understanding the Limitations of Music Box Composition

When composing for a music box, several limitations must be considered. Unlike other instruments, notes cannot be placed freely, which means some songs may not be suitable for a music box.

1. Understanding the 18-Note Mechanism

Although this is an 18-note music box mechanism, it does not mean there are 18 distinct notes available. The comb consists of 18 teeth, but some are tuned to the same pitch, reducing the number of unique notes that can be used.

Composing a tune for a music box is not as simple as placing notes freely. There is no fixed guideline dictating how many notes can be used or how many repeated notes are allowed. Instead, the composition process follows a mathematical formula. We simulate all notes of a tune in our software, perform calculations, and determine whether the song is feasible. This process is handled entirely by our musicians and engineers.

2. Constraints in Music Box Composition

• A music box cannot play more than two notes simultaneously.
• The playable range is limited to 2.5 octaves.
• The key of the tune is not fixed. Our software automatically calculates the best key for the production process, which may differ from the original key.
• Pins cannot be placed too close to each other.

3. The Problem with Closely Positioned Pins

As shown in the figure below, the red circle highlights three consecutive pins placed too closely together. When this happens, the vibration of the comb caused by the first pin has not yet stopped when the second pin strikes the same tooth. This results in a creaking noise. To prevent this issue, careful planning is required when positioning the pins.

Solution: Splitting the C Note Across Multiple Rows

Instead of using a single row for the C note, the note is divided into three separate rows, each strummed by a different section of the comb. This arrangement prevents the pins from clustering together, as shown in the actual pin layout below.

However, since three out of the 18 teeth are now dedicated to the C note, fewer teeth remain available for other notes, limiting the number of notes that can be used in the composition.

4. The Effect of Multiple Teeth Producing the Same Note

Using multiple teeth for the same note can introduce distortion. This is because teeth with the same pitch share the same natural frequency.

For example, tooth #1 and tooth #2 may both be tuned to the C note at 523 Hz. When tooth #1 is strummed, tooth #2 will also vibrate due to resonance. To resolve this, we must alter the natural frequency of tooth #2. However, this adjustment introduces a slight distortion in the note’s sound.

5. Why Creaking Is Harder to Avoid in Lower Notes

Lower notes have longer teeth, meaning they vibrate for a longer duration. This makes it significantly more difficult to place repeated low notes without experiencing creaking issues. A song with many closely spaced low notes is much harder to produce without unwanted noise.

6. Our Solution to the Creaking Issue

At Only One Music Box, we have developed a technique to reduce creaking by minimizing the teeth’s vibration duration. This allows us to position pins closer together, enabling us to fit more notes onto the comb while maintaining the quality of the song.