Tempi changes refer to the sequential flying changes a horse performs at set intervals across a diagonal line in the dressage arena. These changes can be executed every stride (one-tempis), every two strides (two-tempis), and so forth. The number of strides between changes decreases as the level of difficulty increases, with one-tempis being the most challenging and indicative of high-level dressage training. Tempi changes test the horse's agility, precision, and ability to maintain a rhythmic canter while seamlessly switching leads. This movement requires meticulous timing and coordination from the rider to cue the changes accurately and is a highlight in Grand Prix dressage routines, demonstrating the pinnacle of horse and rider synchronisation.