Longwise sets for Couples are formed with the Men Standing in one line Down the room and their Partners in a parallel line Facing them. In a wide ballroom, there will be several such lines of dancers. The Top couple of the first Set is nearest to The music; from the dancer's point of view as s/he looks towards The music, the Men's Side line is on the left and the Ladies' on the right.
At a Ball, the Top couple should establish the width of The set, adjusting the width and the distance from each adjacent Set to a fair share of the amount available if the ballroom is crowded. The Top man should count the appropriate number of Couples for each Set starting from the Top and counting primarily on the Men's Side; he should indicate clearly to the MC if more Couples are required to complete the Bottom Set and, if so, how many. It is wise to check by counting The sets backwards once they are Made up.
As the lines build up, other Couples should join from the Bottom, never breaking into a partially formed line; the Men and Ladies should line up according to the width established by the Top couple. If a Lady has joined the line without her Partner (for example when he is MC), she should stand in the Men's line before the counting starts and stay there until her Partner arrives.
When Beginners are involved in a dancing class, it is helpful to them if the Lower Sets, after being Made up, are moved Down so that there is a clear space between adjacent Sets.
For most purposes in this section, each Couple is numbered according to their Place in the Full set, i.e., the Place in which they started the dance. For matters concerning the current Repeat of a dance, each Couple is also numbered according to the Place in which they started this Repeat; where there is any risk of confusion, Place numbers are qualified with "in the Active set" or "in the Full set" as appropriate.
In the diagrams, the numbered Places in which the Couples started the dance are shown in Times New Roman font; the numbered Places in which they started the Repeat are shown in Helvetica font.
The various formats of Longwise sets are distinguished by the number of Couples dancing in each Repeat and by the number of Couples required to form the Full set; for example, 3 Couple repeat in 4 couple set defines the format of Full set requiring 4 Couples of whom 3 Couples are performing in the Active set at any time.