What are tempi changes and are they relevant to western performance horses?

Tempi changes are a series of flying lead changes executed at regular intervals — every stride (one-tempi), every two strides (two-tempi), every three strides (three-tempi), or every four strides (four-tempi). They are most commonly associated with upper-level dressage competition and are not standard requirements in western performance disciplines, but understanding them provides context for the systematic development of lead changes and has occasional relevance to western horses. In dressage, tempi changes are Grand Prix movements that represent the pinnacle of collection and gymnasticization — a horse that can execute clean, rhythmic one-tempi changes (changing lead every stride) has developed extraordinary collection, balance, and responsiveness. The training progression that produces tempi changes — from simple changes to flying changes to four-tempi to three-tempi to two-tempi to one-tempi — is a logical systematic development of the horse's physical ability and responsiveness. For western performance horses, the four-tempi and three-tempi concepts are occasionally referenced in western riding and reining development, specifically when training horses to change at specific intervals reliably. A horse that can change every four strides on command has developed a level of responsiveness and timing that transfers directly to the western riding pattern's specific change placement requirements. The systematic nature of the tempi progression — always working from longer intervals to shorter — is applicable to western lead change development even if the one-tempi changes themselves are not a goal. Clinton Anderson's approach to developing consistent, placeable lead changes follows a similar progressive refinement of the timing and responsiveness, even if the specific terminology of tempi changes is not typically used in his western horsemanship framework.