A song with some popularity in certain circles is about working together. It’s from “Sesame Street,” which as everyone knows is for little children. Gov. Andrew Cuomo and Mayor Bill de Blasio might want to give it a listen. They could learn a thing or two, starting with the song’s title, “Cooperation Makes It Happen.”

Bickering between the New York State governor and the New York City mayor is time-honored, and Messrs. Cuomo and de Blasio have adhered to that unhappy tradition on a range of issues. But an exercise that was merely tedious has become corrosive in the crisis afflicting the city’s subways. Both men need to knock off the finger-pointing and absorb the lesson learned by watching Big Bird.

The new chairman of the Metropolitan Transportation Authority, Joseph Lhota, seemed to sense that need on Tuesday when he pulled back from the political fray he had previously entered, essentially on the governor’s side. It’s good he seems to recognize that he risks undermining his role as a neutral force riding to the rescue.

On the substance of improving subway service, a sensible starting point for debate is a short-term plan Mr. Lhota announced to repair track signals, improve maintenance and communications, and experiment with removing some seats on a couple of lines to increase train capacity. On Monday, Mr. de Blasio offered his own proposals, as did the transit workers’ union. There will be time on another day to explore in detail the merits of these recommendations.