The two also performed Ed's new single "Azizam" at the 50th St. subway station in the latest "Subway Busking" segment on Tuesday night (April 8).
The singer and "The Voice" judge didn't have a lot of specific details on Monday night (April 7), but promised that things are definitely happening.
He also told Jimmy Fallon about hitting up his pal Bonnie Raitt for permission to sample one of her songs for a Charli XCX remix.
The trio also played the "Name That Song Challenge" game on Wednesday night's (March 5) "Tonight Show."
"I mean, the first time we ever sang in front of each other was actually at my MSG show last year," McRae revealed on The Tonight Show.
"I think people are usually pretty surprised when they come to see me in concert, especially if they only know me for the songs on the radio," Halsey said on Fallon.
