How does a musical note’s shape show its duration?

In Western musical notation, a note’s shape serves as a primary indicator of its relative duration. Rather than relying solely on horizontal spacing, the specific design of the note—including whether the note head is filled or open, and the presence or absence of stems and flags—defines its rhythmic value in relation to other notes.12

Each standard note symbol represents half the duration of the note value preceding it. Common modern note shapes include:2

• Whole note: An open, oval note head without a stem.1
• Half note: An open note head with a stem.1
• Quarter note: A filled (solid) note head with a stem.1
• Eighth note: A filled note head with a stem and one flag.1
• Sixteenth note: A filled note head with a stem and two flags.1

Further subdivisions, such as thirty-second and sixty-fourth notes, continue this pattern by adding additional flags to the stem. Additionally, a dot placed to the right of a note head increases its duration by half of its original value.12