1. What is the Keyboard Notes Formula?

The Keyboard Notes Formula calculates the frequency of musical notes based on their distance in semitones from the reference note A4 (440 Hz). This formula is fundamental in music theory and instrument tuning.

2. How Does the Calculator Work?

The calculator uses the keyboard notes formula:

Where:

• \( f \) — Frequency in Hertz (Hz)
• \( n \) — Number of semitones from A4
• 440 — Reference frequency of A4
• 12 — Number of semitones in an octave

Explanation: The formula uses the equal temperament system where each semitone represents a frequency ratio of \( 2^{1/12} \).

3. Importance of Frequency Calculation

Details: Accurate frequency calculation is essential for musical instrument tuning, sound engineering, music composition, and understanding the mathematical relationships between musical notes.

4. Using the Calculator

Tips: Enter the number of semitones from A4. Positive values for notes above A4, negative values for notes below A4. For example, C5 is +3 semitones, A3 is -12 semitones.

5. Frequently Asked Questions (FAQ)

Q1: Why is A4 used as the reference note?
A: A4 at 440 Hz is the international standard for musical pitch, known as concert pitch or Stuttgart pitch.

Q2: What frequency is middle C (C4)?
A: Middle C is -9 semitones from A4, giving a frequency of approximately 261.63 Hz.

Q3: How accurate is this formula?
A: This formula provides the exact frequencies used in equal temperament tuning, which is the standard for most Western music.

Q4: Can I calculate frequencies for microtones?
A: Yes, you can use fractional semitone values (e.g., 0.5 for quarter tones) to calculate microtonal frequencies.

Q5: What's the frequency range of a standard piano?
A: A standard 88-key piano ranges from A0 (27.5 Hz, -48 semitones) to C8 (4186.01 Hz, +51 semitones).