In the process of playing stringed instruments where the strings lie over a fingerboard, the strings are said to be "stopped" when they are pressed against the fingerboard to alter the open-position interval of the string. Stopping, or pressing against the string, actually shortens the string relative to its open or unstopped position thus increasing its frequency and tonal structure. Accordingly, melodic lines, harmonies, and arpeggiated and blocked chords are a result of stopping positions and techniques. (See "stopped tones" concerning "stopping" and brass instruments.)