Why was barnett newman's painting cathedra attacked in 1997?

The attacker claimed he and Newman completed "Who is afraid of Red, Yellow, and Blue" together and hated how the restoration was done. However, it wasn't up when he went, so he took out a knife and destroyed Cathedra. I do not remember his name. I believe it was in 1997.

a chromatic scale uses the twelve tones of the octave, while a regular scale only uses eight, or seven different notes (as the first note is played twice)