Teal Sound.... utilized Rock Guitars in the World Class Division DCI Field competition for the first time, a few years back. That was a first, imo. I have no idea how the Rock Guitar performance execution is judged, nor what caption judge judged the playing that season, nor what the judges training, qualifications are on the proper playing technigues, sound quality, to come from the Rock Guitar instrument and from the Corps Rock Guitar performers. My guess, nobody else here can say for certain either.( haha!). Its a leap of faith when it comes to DCI judging and how they do their thing. Same as it ever was. But Teal Sound's utilization of Rock Guitars was " unexpected " for me. Heck, I did not even know DCI had approved this musical instrument for Field competition, until I saw it being judged on the field that season. Thats how " unexpected " it was for me as a long time fan when I saw it for the first time out there.