If you were looking for Reels as the musical tempo of a Scottish Country Dance, see Types of dance.
In a Reel, the Dancers Travel (using Skip change or the Strathspey travelling step according to the tempo of the dance) all going in the same direction on a single path which has one or more crossing points. Provided the Dancers are evenly spaced around the path and Travel at a steady speed, there is no risk of collision and so no consideration arises over Precedence. For example, the diagram shows sixteen successive movements which, together, make up the full Reel of four.
Idealized Reel of Four.
Successive Positions in an idealized Reel of four, each movement being 1/16 of the full Figure; arrow heads show the Positions of the equally spaced Dancers after each half bar. The vertical lines show the axis of the Reel of four; when danced on the Side lines of a 4 Couple, Longwise set, the horizontal lines show the 1st, 2nd, 3rd and 4th positions in The set.
Although the Dancers should be evenly spaced and Travelling at constant speed throughout most of any Reel, it is only rarely that a precursor Figure leaves them in the evenly-spaced Positions required for the Reel and never so if they start from Standing Places. Usually, some of the Dancers will have to start quickly and some slowly in order to achieve the even spacing. This consideration is covered under the individual forms, Reel of four and so on.
Although the full Reel of three is mostly performed in 8 bars, it works well in 6 bars which is probably the natural allocation; the 6 bar form occurs in bars 25-30 of General Stuart's Reel and many other dances where the remaining two bars of the 8 bar Phrase are used to return the Dancing couple to their Own sides.
For the mathematically minded, the Reel of N is for N Dancers, it has a path with N-2 crossing points, there are N-3 extra passing loops between the loops at the ends and the full Figure requires 2N bars as a minimum.
Reels for an odd number of Dancers have a clockwise loop at one End and an anticlockwise loop at the other. Reels for an even number of Dancers have clockwise loops at both Ends in the normal form and anticlockwise loops at both Ends in the, less common, reverse form.
Similar alignments occur in Square and Triangular sets but, in addition, the axis is sometimes distorted into a curve around the edge of The set, i.e., around the arc joining the Dancers Places. Schiehallion Reels (in Square and Triangular sets) obey the rule for Reels that all the Dancers Travel in the same direction and are equally spaced at 2 bar intervals around a single path though in this form there is no sense of going out along the axis and then returning along it; instead, the Dancers proceed around the edge of The set to Finish in their Starting Positions.
Interlocking reels involve multiple Reels either overlapping or sharing parts of their paths.
In some derivative forms, one or more Dancers in a Reel are replaced by two Dancers who Dance as one person, following the path of the Dancer replaced; these two Dancers may Travel in Tandem (often with the lead changing as in the Alternating tandem reel of three) or in Promenade hold or Allemande hold or with Nearer hands joined (as in Hand-in-hand reels of 3).
Details of Reels for a specific number of Dancers are in the pages Reel of three, Reel of four and so on and in the pages subsidiary to these.
Although some forms are superficially similar to Reels, Figures of eight are logically different; they are sometimes danced around one or more Standing Dancers and often involve crossing paths which do require one Dancer to give Precedence to another, as for example in the form of Figures of eight across in which the Dancers either both Cross up or both Cross down to start.