🎼 music

I'm back on learning music, so I'll document here the stuff I've been learning.

Music Theory 101

It's important to know what are the basic building blocks of music, right?

Music Notes

The basic building block of music is a note. They are represented by English charaters A-G (A, B, C, D, E, F, and G). We know them by the solfège do–re–mi–fa–sol–la–si, which translates to the characters C, D, E, F, G, A, and B (it starts on C because it's the equivalent to do, with D being the equivalent to re, and so on).

Notes can be modified by accidentals, creating intermediary notes between each one. The sharp sign (#) raises a note by a semitone (or half-step), while a flat (or bemolle) lowers note by a semitone. So, c C# would be a note that exists between C and D, while E♭ would be a note that exists between D and E. It's also possible to have a semitone represented by two possible accidentals - for instance, the C# one could also be represented by D♭. Since the sharp sign raises one semitone and bemolle lowers one semitone, the two representations are equivalent.

Note: there are some special notes that does not have intermediary semitones. The B and C, and the E and F. These ones does not have semitones between them, so the semitones B#, C♭, E# and F♭ does not exist.

The full list of notes and sharp semitones would be:

C C# D D# E F F# G G# A A# B

The equivalent full list of notes and flat semitones would be:

C D♭ D E♭ E F G♭ G A♭ A B♭ B

Scales and Tetrachords

In music, a scale is an ordered set of musical notes. One of the most common scales is probably the C Major: C, D, E, F, G, A and B. It has no sharps or flats, and can easily be played on piano by just hitting the white keys starting on C.

A tetrachord is a set of four notes separated by three intervals. Tetrachords are the basic building blocks of a major scale, and its notes are systematically spaced by the following rule: whole step, whole step, half step, with a whole step separating the tetrachord from the second one. This way you can draw any major scale by just starting from a given note and following the tetrachord spacing order.

Using the tetrachord schema, I could describe the logic behind the C major with:

C major (C D E F G A B): the first tetrachord goes one whole step (full note) from C to D, one whole step from D to E, and a half step (semitone only) from E to F (remember, there are no semitones between E and F). Then one whole step to start the second tetrachord at note G. Then, one whole step from G to A, one whole step from A to B, and one half step from B to C (again, there are no semitones between B and C).

Below are some other major scales I'm writing through the tetrachord system (I'm checking them on Wikipedia right after writing, and they are correct - yeah!):

• D major: D E F# G A B C# D
• E major: E F# G# A B C# D# E
• F major: F G A A# C D E F
• G major: G A B C D E F# G
• A major: A B C# D E F# G# A
• B major: B C# D# E F# G# A# B