Gore's bandmate Dave Gahan admits he had no idea who the guy watching their session was until an engineer revealed he was the man behind hit album Channel Orange - and a big fan.
Gahan tells Ew.com, "We were in the studio in New York, and we were filming and recording some live tracks toward the end of the session. I was singing, Martin on guitar, (with) a few of the other guys. Suddenly, in the doorway, I sensed this presence, and I realised there was this guy standing there just watching.
"An assistant came up to me in between songs and said, 'Do you mind? Frank Ocean is here working in another studio and really wants to meet you guys'. I wouldn't have thought he would have even known who we are, but it turns out he's a big fan."
The meeting took place and Gore agreed to work with Ocean on a new tune.
Gahan adds, "He ended up doing a track with him, which I think is going to be part of his new record. Martin did some electronics and some modular synthesizer stuff he really wanted."