<P> In music, a melody of four pitches where a straight line drawn between the outer pair bisects a straight line drawn between the inner pair, thus forming a cross (as in the red lines in the example to the right). In its simplest form, the cruciform melody is a changing tone, where the melody ascends or descends by step, skips below or above the first pitch, then returns to the first pitch by step . Often representative of the Christian cross, such melodies are cruciform in their retrogrades or inversions . Johann Sebastian Bach, whose last name may be represented in tones through a musical cryptogram known as the BACH motif that is a cruciform melody, employed the device extensively . The subject of the fugue in c - sharp minor from The Well - Tempered Clavier Book I is cruciform . See also: Cross motif . </P> <P> The plain sword used by knights, distinctive due to the flat bar used as a guard . The overall shape of the sword when held point down is that of a cross . </P> <P> It is believed this shape was encouraged by the church to remind Knights of their religion . It was however very popular due to the protection it offered to the hand and certain attacks that rely on the cross to trap the blade of the enemy . See Sword . </P> <P> Some airplanes use a cruciform tail design, wherein the horizontal stabilizer is positioned midway up the vertical stabilizer, forming a cruciform shape when viewed from the front or rear . Some examples are the F - 9 Cougar, the F - 10 Skyknight and the Sud Aviation Caravelle . </P>

What are the five parts to the cruciform style church