Reviews of the premiere performance of "Boris Godunov" were for the most part hostile. Some critics dismissed the work as "chaotic" and "a cacophony". Even his friends Mily Balakirev and César Cui, leading members of the Mighty Handful, minimized his accomplishment. Unable to overlook Mussorgsky's "trespasses against the conventional musical grammar of the time", they failed to recognize the giant step forward in musical and dramatic expression that "Boris Godunov" represented. Cui betrayed Mussorgsky in a notoriously scathing review of the premiere performance: