Pitch is the backbone of music, determining how high or low a sound is. It's measured in frequency, with higher frequencies producing higher pitches. Understanding pitch is crucial for reading and writing music, as it forms the basis of our musical notation system.

The musical staff, with its five lines and four spaces, provides a visual representation of pitch. Clefs, like treble and bass, help musicians interpret which notes correspond to which lines and spaces. This system allows for precise communication of musical ideas.

Pitch and Frequency

Understanding Pitch

• Pitch is the perceived frequency of a sound, determined by the number of vibrations per second
• Higher frequency sound waves result in higher perceived pitch, while lower frequency waves result in lower perceived pitch
• The human ear can typically hear frequencies between 20 Hz and 20,000 Hz (20 kHz), although this range varies among individuals and decreases with age
• In Western music, pitch is organized into a system of notes with specific frequencies (A4, the A above middle C, at 440 Hz)

Frequency and Pitch Relationship

• Frequency is measured in Hertz (Hz), which represents the number of vibrations or cycles per second
• A sound wave with a frequency of 100 Hz means that it completes 100 vibrations or cycles in one second
• Doubling the frequency of a pitch results in a pitch that is one octave higher (A4 at 440 Hz, A5 at 880 Hz)
• Halving the frequency of a pitch results in a pitch that is one octave lower (A4 at 440 Hz, A3 at 220 Hz)

Reading and Writing Pitch

The Musical Staff

• The musical staff consists of five horizontal lines and four spaces, each representing a specific pitch
• Clefs are symbols placed at the beginning of the staff to indicate the pitch range and assign specific pitches to lines and spaces
• The treble clef, also known as the G clef, is used for higher-pitched instruments and voices and indicates that the second line from the bottom represents G4
• The bass clef, also known as the F clef, is used for lower-pitched instruments and voices and indicates that the fourth line from the bottom represents F3
• The C clef, including alto and tenor clefs, is used for middle-range instruments and voices, with the center of the symbol indicating the location of middle C (C4)

Ledger Lines and Extended Pitch Range

• Ledger lines are short lines added above or below the staff to extend the pitch range when necessary
• Notes above the treble clef staff use ledger lines to represent higher pitches (A5, C6, E6)
• Notes below the bass clef staff use ledger lines to represent lower pitches (E2, C2, A1)
• Multiple ledger lines can be used to extend the pitch range even further (G6, F7 in treble clef; G1, E1 in bass clef)

Note Names and Piano Keys

White Keys and Note Names

• The white keys on a piano keyboard correspond to the notes A, B, C, D, E, F, and G, with each letter representing a specific pitch
• The pattern of white keys repeats across the entire keyboard, with each repetition representing a different octave
• The lines and spaces of the treble clef staff correspond to the notes E, G, B, D, and F (lines) and F, A, C, and E (spaces), from bottom to top
• The lines and spaces of the bass clef staff correspond to the notes G, B, D, F, and A (lines) and A, C, E, and G (spaces), from bottom to top

Black Keys and Accidentals

• The black keys on a piano keyboard are used to play sharp (♯) and flat (♭) notes, which fall between the white keys
• A sharp raises a note by a half step, while a flat lowers a note by a half step
• The black key between C and D is C♯ (sharp) or D♭ (flat), depending on the musical context
• The black key between E and F is E♯ or F♭, although these are less common due to the half-step distance between E and F

Octaves and Pitch Organization

Octave Intervals

• An octave is the interval between two pitches with a frequency ratio of 2:1, meaning the higher pitch vibrates twice as fast as the lower pitch
• Pitches with the same letter name that are an octave apart are perceived as similar and have a strong musical relationship (C4 and C5)
• The standard piano keyboard spans over seven octaves, with each octave containing 12 pitches (7 white keys and 5 black keys)

Chromatic Scale and Half Steps

• In Western music, pitches are organized into a repeating pattern of 12 semitones (half steps) within each octave, resulting in a chromatic scale
• The distance between two adjacent keys on a piano, whether white or black, is a half step or semitone
• Two half steps equal a whole step or whole tone, which is the distance between two white keys with a black key between them on the piano (C to D, D to E)
• The chromatic scale includes all 12 pitches within an octave, arranged in ascending or descending order by half steps (C, C♯, D, D♯, E, F, F♯, G, G♯, A, A♯, B)