Notes and frequency

Notes are musical units in a melody. In Western music, notes have symbols from A to G which repeats itself when it ends, which means that G is followed by an A. Here are the notes:

La Si Do Re Mi Fa Sol

As you can realize, B-C and E-F notes are closer. There are 2 semitones between each 7 notes except B-C and E-F. They have only 1 semitone in between.

There are two special symbols to represent semitone differences:

So we can complete the table for 12 notes now. Note that a #-note is same with a b-note.

Note Symbols

La La sharp
Si bemol
Si Do Do sharp
Re bemol
Re Re sharp
Mi bemol
Mi Fa Fa sharp
Sol bemol
Sol Sol sharp
La bemol
A A#
B C C#
D D#
E F F#

Example Sound Wave of a Note

So why different sounds are formed on different instruments when playing the same note? There are many other frequencies in a note. The frequencies and their magnitude characterize the sound. However, we will not go into the details here because we want to learn to play an instrument as quick as possible :)

When you play a note on an instrument, you hear many frequencies, however each note has a dominant frequency. Below, dominant frequency is the thickest one, which has the biggest amplitude. This dominan frequency is always the same even if you play the note on different instruments.

Note-Frequency Table

We can represent notes with their dominant frequency. Below table shows the dominant frequencies of notes.

Note Frequency (Hz)
C 33
C# / Db 35
D 37
D# / Eb 39
E 41
F 44
F# / Gb 46
G 49
G / Ab 52
A 55
A# / Bb 58
B 62

Next we will learn about octaves.