Sixteenth notes are a type of musical note that represents a specific duration of sound. In standard music notation, they are depicted as a filled-in oval note head 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 faster rhythms and add complexity to a piece. They are commonly found in various genres, including classical, jazz, and pop music. Musicians often count sixteenth notes using the syllables "1 e and a" to keep track of the timing.