 Routines from the classically derived style of contemporary dance are the most common dances seen on the show, being seen in every performance episode of the series (and typically at least twice per episode).While contemporary, lyrical, and modern dance are typically considered three separate (if overlapping) styles of dance, the practice on "So You Think You Can Dance" has been to refer to all routines in this area as "contemporary", except in the first season where the label "lyrical" was used for the same purpose.Ballet routines occur much more rarely, at a rate of one or two per season since their introduction in the fourth season.