Note values and dotted notes: calculate the duration

A quarter note is half the duration of a half note and twice the duration of an eighth note. Those relationships do not change when the music speeds up. The number of counted beats each note receives depends on which note value represents your beat. Source: Music Theory for the 21st-Century Classroom, durational symbols.

For every calculation on this page, use 4/4 with a quarter note equal to one beat. This makes the arithmetic easy to inspect. In a different metre or counting system, identify the unit again instead of treating “quarter note equals one beat” as a universal definition.

The table names durations in words. To recognise their printed shapes, follow the source’s notation examples or work with a teacher’s score; do not infer note length from the horizontal space a publisher happens to leave on the page.

You may meet either UK or US terminology in Indian lessons and exam materials. The names below refer to the same values. Source: Open Music Theory, note-value terminology.

Read across one row, then compare two rows. Two eighth notes occupy the same total time as one quarter note, but have two separate beginnings. Four sixteenth notes also fill one quarter-note beat. Equal total duration does not mean identical rhythm.

Check the word “whole” carefully: a whole note fills a 4/4 bar under this convention, but it is not a universal symbol for any complete bar. A 3/4 bar normally contains three quarter-note beats, not four.

For a single dotted note, calculate the undotted value, divide it by two, then add that amount. A dotted half note is 2 + 1 = 3 beats here. A dotted quarter is 1 + 1/2 = 1½ beats. A dotted eighth is 1/2 + 1/4 = 3/4 of a beat. The dot does not always add one beat. Source: Music Theory for the 21st-Century Classroom, dots and ties.

Use an original four-position subdivision to check the dotted eighth: count “1 e and a” evenly within a single beat. Start the dotted eighth on 1; it occupies the first three positions. The final sixteenth begins on “a”. Together, 3/4 + 1/4 makes one full beat.

If fractions hide the pattern, draw four small boxes instead. Shade three for the dotted eighth and one for the sixteenth. Label the whole row “one quarter-note beat”. This makes the unit visible and prevents you from accidentally treating each box as a whole beat.

A tie connects notes at the same pitch and combines their durations. A quarter note tied to an eighth lasts 1½ beats in our exercise, with no new attack where the eighth begins. Two untied notes of those values occupy the same time but begin separately. A slur is a different marking and should not be treated as an instruction to add all its notes into one pitch. Source: dots and ties.

Write “start, continue” under the tied pair and “start, start” under the untied pair. Say one long sound for the first, then two sounds for the second. You are checking the distinction between duration and articulation; the tie does not grant extra time beyond the values it connects.

Use the same 4/4 quarter-note beat. Each question asks for the missing duration, not a particular pitch or fingering.

1. A dotted quarter, an eighth and a half note: does the bar total four beats?
2. A dotted half note begins on beat 1. What single undotted note value can fill the rest of the bar?
3. A quarter note tied to a quarter is followed by two eighths. How much time remains?
4. Someone writes “a dotted eighth equals one and a half beats”. What assumption should you ask them to state?

Check the calculations

1. Yes: 1½ + ½ + 2 = 4.
2. A quarter note: 3 + 1 = 4.
3. One beat remains: the tied pair totals 2, and the eighths total 1.
4. Ask which note value represents one beat. If it is an eighth, their count can be valid; with our quarter-note beat, a dotted eighth is ¾.

For another counting context, compare simple and compound metre. Keep one calculation in your practice notes; if preparing an assessment, confirm the required terminology with your teacher and the current exam pathway.