Phase 2, who in the early 1970s was one of the most prolific, inventive and emulated New York graffiti writers, and who later produced early hip-hop’s most innovative fliers, died on Dec. 12 at a nursing and rehabilitation center in the Bronx. He was 64.

The cause was amyotrophic lateral sclerosis, also known as Lou Gehrig’s disease, his longtime friend David Schmidlapp said.

In the South Bronx at the dawn of the 1970s, all the creative components that would coalesce into what became widely known as hip-hop were beginning to take shape. At the center of them all was Phase 2, an intuitive, disruptive talent who first made his mark as a writer of graffiti — although he hated the term.

“He had a natural gift or ability to stylize letters,” said Alan Ket, a founder of the Museum of Graffiti in Miami, adding that he “continued to develop styles that were pioneering or just wildly innovative.”