Sixteenth notes are a type of musical note that represents a specific duration of sound. In standard music notation, they are written as a filled-in oval with a stem and two flags. Each sixteenth note lasts for one-fourth the duration of a quarter note, meaning four sixteenth notes can fit into one quarter note. In a measure of music, sixteenth notes are often used to create fast rhythms and intricate patterns. They are commonly found in various musical genres, including classical, jazz, and pop. Musicians often count sixteenth notes using the syllables "1 e and a" to keep track of the timing.