A J-Rock song by Baroque (brq), by many considered to be the absolute low of their career. Within J-Rock circles "Gakidou" is used to express that something is uninspired and it probably is time to put an end to it to save any further embarrassment.
A clip of said song can be found on video.google.com by searching for Brq Gakidou.
Person A: Did you hear Janne da Arc's Shining Ray?
Person B: Yeah, it's awful. I think it would be for the best if they pulled a gakidou.
Person A: Let's go back to listening to L'Arc~En~Ciel instead.