Sound, pitch and notes
Musical sound comes from vibrations. Pitch is how high or low a sound is. Faster vibration (higher frequency, in hertz, Hz) means a higher pitch.
- Western music names seven notes: C D E F G A B. Indian music uses Sa Re Ga Ma Pa Dha Ni (the swaras).
- After B comes C again, one octave higher. The frequency doubles: C4 ≈ 262 Hz, C5 ≈ 523 Hz. In Indian music this is the next saptak.
- The smallest step on a keyboard is a semitone (half step). Two semitones make a tone (whole step). An octave has 12 semitones.
- A sharp (♯) raises a note by a semitone; a flat (♭) lowers it. The black keys are sharps/flats.
Notes are written on a staff of five lines. A treble clef is used for higher notes, a bass clef for lower notes. Many traditions also use letters or sargam syllables instead of a staff.
Rhythm: beat, tempo, note values and time signatures
The beat is the steady pulse you tap your foot to. Rhythm is the pattern of long and short sounds over the beat. Tempo is the speed, in beats per minute (BPM).
| Note value | Beats (in 4/4) |
|---|---|
| Whole note (semibreve) | 4 |
| Half note (minim) | 2 |
| Quarter note (crotchet) | 1 |
| Eighth note (quaver) | ½ |
| Sixteenth note (semiquaver) | ¼ |
Each note has a matching rest (silence) of the same length. A dot after a note adds half its value (dotted half = 3 beats).
Beats are grouped into bars (measures). The time signature tells how many beats are in a bar: 4/4 (four quarter beats, common in pop), 3/4 (three, like a waltz), 2/4 (two, like a march). Indian music groups beats into a taal cycle, such as Teentaal with 16 beats.
Scales, intervals and chords
A scale is a set of notes in order of pitch. The major scale uses the pattern T T S T T T S. From C it uses only white keys; from another note it needs some sharps or flats. The natural minor scale uses T S T T S T T and often sounds sadder or darker. A raga is richer: it also sets which notes rise, fall and are stressed.
An interval is the distance between two notes, counted by letter names: C to E is a 3rd, C to G a 5th, C to C an octave.
A chord is two or more notes played together. A triad stacks a root, a 3rd and a 5th: C major = C E G; F major = F A C; G major = G B D. Chords played one after another form a chord progression; I–IV–V (C–F–G) is used in thousands of songs. Chords make the harmony; the tune on top is the melody.
Other elements: dynamics, timbre, texture and form
- Dynamics: how loud or soft. p (piano) = soft, f (forte) = loud; crescendo = getting louder.
- Timbre (tone colour): what makes a flute sound different from a sitar on the same note.
- Texture: how many layers. One melody alone (monophonic), melody with chords (homophonic), several melodies together (polyphonic).
- Form: the plan of a piece. Binary (AB), ternary (ABA), verse–chorus in songs; sthayi–antara in many Indian songs.
To analyse a piece, listen for each element, name it with these words, and say how it creates a mood. To create, start with a short rhythm, add a melody from a scale, then chords, then shape it with dynamics and form. Music software and recording (a technique and technology) let you layer and edit parts. Music also reflects its society: work songs, festival music and film songs carry stories and values.
Try it
Clap a steady beat and count 1-2-3-4. Now clap only on 1 and 3, then on every half beat. You just changed rhythm over the same beat. Hum Sa Re Ga Ma Pa Dha Ni Sa and notice the two small steps (Ga–Ma and Ni–Sa).
Key formulas and definitions
- Octave: frequency × 2 (C4 ≈ 262 Hz → C5 ≈ 523 Hz); 12 semitones
- Tone = 2 semitones
- Major scale: T T S T T T S; natural minor: T S T T S T T
- Note values in 4/4: whole 4, half 2, quarter 1, eighth ½, sixteenth ¼
- Dot adds half the note's value
- Triad = root + 3rd + 5th (C major = C E G)
- Time signature: top = beats per bar, bottom = note value of one beat
Worked examples
1. A (the note) vibrates at 440 Hz. What is the frequency of A one octave higher? One octave lower?
Higher: 440 × 2 = 880 Hz. Lower: 440 ÷ 2 = 220 Hz.
2. In 4/4 time, how many beats are in: half note + quarter note + two eighth notes?
2 + 1 + ½ + ½ = 4 beats: exactly one full bar.
3. How many beats does a dotted half note last in 4/4?
Half = 2, the dot adds half of 2 = 1, so 3 beats.
4. Build the G major scale using T T S T T T S.
G –T→ A –T→ B –S→ C –T→ D –T→ E –T→ F♯ –S→ G. It needs one sharp: F♯.
5. Name the notes of the F major triad.
Root F, 3rd A, 5th C: F A C.
6. A song is at 120 BPM. How long does one bar of 4/4 last?
120 beats per minute = 2 beats per second, so one beat = 0.5 s. Four beats = 2 seconds.
Common mistakes
- Thinking there is a black key between every pair of white keys. There is none between E–F and B–C (these are semitones).
- Mixing up tempo (speed) and rhythm (pattern of long and short notes).
- Forgetting that a dot adds half of the note's own value, not one beat.
- Calling any loud sound "high". High and low mean pitch; loud and soft mean dynamics.