Last night, Frank Ocean released his new visual album, Endless. The audio begins with a German-accented voice, over a bed of flickering electronics, intoning, “With this Apple appliance, you can capture live videos.” The same voice returns at the end of Endless, as part of a gleaming techno-pop song that takes up about the last seven minutes of the album. Today, acclaimed German fine-art photographer Wolfgang Tillmans, who also releases music under his own name as well as with his band Fragile, said on Instagram that both of the tracks bookending Endless incorporate his own unreleased track “Device Control.”

Tillmans wrote that he shared a few tracks with Ocean a few weeks ago, then was surprised and excited to find that Ocean didn’t just sample it: “He released my complete original track at the end of this amazing album.” Tillmans’ track is from his Device Control EP, which he will release digitally tomorrow, August 20. The EP, out physically on September 16 via Fragile, also includes remixes of Tillmans’ “Make It Up As You Go Along” by Daniel Wang & J.E.E.P. as well as Salem. Today, Tillmans chatted with Pitchfork over email about how the collaboration came to be.

Pitchfork: How did you first happen to get in touch with Frank Ocean?

Wolfgang Tillmans: We were brought together by the wonderful people at Fantastic Man magazine, who had set up an exclusive cover story for their 10th anniversary album early last year. The shoot turned out to be almost impossible to set up. Frank and I would telephone a few times, and then he would cancel on the evening before the shoot in London, reschedule for the next day, then cancel again. I had given up hope and said I had to go to Berlin next day. He said he would prefer to do it there. I didn’t think he meant it, but two days later he showed up at my Berlin studio, having driven 12 hours through the night from London.

What was your interaction like?

We immediately got on, and I felt he was a unique artist, and that all the backs and forths were somehow OK. He seemed so well-considered and sharp, yet open to what would happen on the day. At the end of the day, we looked at all the pictures together. He asked about going to [iconic Berlin club] Berghain, but it wasn’t open. He said he might come back on the weekend for it, and drove back to London. Two days later, he indeed showed up again and we went clubbing. All seemed well, but a couple weeks later Fantastic Man got a letter from his lawyers in Los Angeles barring them from using the pictures. It was a huge disappointment and felt very unfair, but we stayed in touch and he later wanted to use images for his book to accompany a future album.