Music cheat sheet

Rhythm, pitch, intervals and tonal relationships.

Rhythm and metre

Rhythm concerns the timing of sounds; metre organises recurring beats. A time signature describes a notated grouping, not every performed accent.

In common 3/4 notation, a bar contains three quarter-note beats.

Pitch and interval

An interval describes the distance between pitches. In Western notation, its number and quality both matter.

C to G is a perfect fifth in the usual diatonic spelling.

Scales and keys

A scale arranges pitches by a pattern. A key concerns tonal relationships and a tonal centre, not only a list of notes.

A major scale follows whole–whole–half–whole–whole–whole–half steps.

Chords

A triad combines a root, third and fifth in a basic tertian model. Inversion changes which chord note is lowest.

C–E–G is a C major triad; E–G–C is an inversion.

Duration and tempo

Note values express relative duration; tempo relates beats to time. A quarter note is not a fixed number of seconds without a tempo and beat convention.

At quarter note = 120, each quarter-note beat lasts 0.5 s.

Interval size and quality

Interval size counts letter names inclusively; quality specifies the pitch distance within that size. Major, minor, perfect, augmented and diminished describe different interval relationships.

C to E is a third; C to E♭ is also a third, with different quality.

Key signatures and tonal centre

A key signature supplies default accidentals, while a tonal centre is established through musical context. Relative major and minor keys can share a key signature.

C major and A minor share a key signature but have different tonal centres.

Texture

Texture describes how musical parts relate: monophony has one melodic line, homophony supports a main melody, and polyphony combines independent lines.

More than one instrument does not automatically create polyphony if they double the same line.

Worked example: bar duration

In 4/4 at quarter note = 120, a bar containing four quarter-note beats lasts 4 × 0.5 = 2 s, assuming a steady tempo.

Changing metre and changing tempo are different changes.

Common mistake: notation fixes performance completely

Notation leaves interpretive choices involving articulation, phrasing, balance and sometimes rhythm or ornamentation. Style and performance practice affect how markings are realised.

Use the score and the musical context when explaining a performance choice.