A quarter note is a basic musical note that represents one beat in a piece of music. It is often depicted as a filled-in oval note head with a straight stem. In standard musical notation, quarter notes are commonly used in various genres, providing a steady rhythm and helping to establish the tempo of a song. In a 4/4 time signature, which is one of the most common time signatures, there are four beats in each measure, and each quarter note receives one beat. Musicians often combine quarter notes with other note values, such as eighth notes and half notes, to create diverse rhythms and melodies.