Rule of thirds intersection of two of the lines, close enough to take advantage of the rule. The rule of thirds is applied by aligning a subject with the guide lines and their intersection points, placing the horizon on the top or bottom line, or allowing linear features in the image to flow from section to section. The main reason for observing the rule of thirds is to discourage placement of the subject at the center, or prevent a horizon from appearing to divide the picture in half. Michael Ryan and Melissa Lenos, authors of the book "An Introduction to Film Analysis: Technique
Major thirds tuning improvisation. In contrast, chords cannot be shifted around the fretboard in standard tuning, which requires four chord-shapes for the major chords: There are separate fingerings for chords having root notes on one of the four strings three–six. The repetition of the major-thirds tuning enables notes and chords to be raised one octave by being "vertically" shifted by three strings. Notes and chords may be shifted "diagonally" in major-thirds tuning, by combining a vertical shift of one string with a horizontal shift of four frets: "Like all regular tunings, chords in the major third tuning can be moved across the fretboard