Background: The Houston Livestock Show and Rodeo, also called RodeoHouston or abbreviated HLSR, is the largest livestock exhibitions and rodeo in the world. It also includes one of the richest regular-season rodeo events. It has been held at NRG Stadium in Houston, Texas, since 2003. It was previously held in the Astrodome.
Context: One of the largest draws for the Houston Livestock Show and Rodeo is the 20 consecutive evenings of rodeo and concert, held in NRG Stadium. Tickets are relatively inexpensive, averaging about $29 in 2016, and also grant admission to the livestock show and fairgrounds. More than 43,000 season tickets are sold every year, with the remaining seats 30,000 seats available for individual-show sale. Members of the HLSR are given an opportunity to buy individual tickets before the general public.  RodeoHouston is run independently of the Professional Rodeo Cowboys Association (PRCA). It offers one of the largest prize purses in North America, over $2 million, but the winnings do not count towards the competitors' qualification for the PRCA National Finals Rodeo. RodeoHouston is an invitational, featuring 280 of the top professional cowboys. They compete in a playoff format, with the ultimate champion in each event earning $50,000. On the final evening, the rodeo hosts the Cinch SuperShootout. Champions from each of the top 10 rodeos in North America are invited to compete as teams in a subset of rodeo events. The finals and the SuperShoot are televised on Fox Sports.  After the professional rodeo concludes, children are given an opportunity to compete. Each evening, 30 high school students from across the state compete in the calf scramble. They are given the opportunity to chase down (on foot) and catch one of 15 calves, put a halter on them, and drag them back to the center of the stadium. Winners are given money to purchase their own heifer or steer to show the following year. Immediately following the calf scramble is mutton busting. Five- and six-year-olds wearing protective gear try to ride a sheep across a portion of the arena. On the last night of the rodeo, the winners from each of the previous evenings compete again to see who will become grand champion.  A rotating stage is then brought into the arena for the nightly concert. The majority of evenings are performances by country music singers, although several nights are dedicated to pop or rock music. The annual Tejano music night generally draws the largest crowds. The winner of the annual Mariachi Invitational competition is invited to perform onstage with the Tejano acts.
Question: What kind of concerts perform?

Answer:
The majority of evenings are performances by country music singers, although several nights are dedicated to pop or rock music.