The duo collaborated on the song "Morning Light," featured on Timberlake's highly anticipated new Man of the Woodsalbum, out Feb. 2. Only ET caught up with Keys on the set of The Voice, where she gushed over how the project came together.
"That's a pretty hard secret to keep," she admitted. "We've been wanting to do a song together for a minute and I remember -- we have even done some writing together and everything like that -- and there's more to come because we have so much synergy."
"I love how he creates," she said of Timberlake's process. "He's very passionate about what he does, he's really inside of himself and inside of the music, and it's just like me, so it's so fresh we have this song together on his album."
So far, Timberlake has released two tracks off MOTW -- "Filthy" and "Supplies" -- with a third, "Say Something" featuring Chris Stapleton, to debuting Thursday.
"I love this record, man" Keys continued. "Every time he comes, I feel like he finds a new piece of himself and I love the way he slightly pushes the boundry a little bit more. It is the best way to be and I'm so excited for him. Y'all are going to love this record."
Also next month, Keys will return for her third stint as a coach on NBC's The Voice, with season 14 set to premiere on Feb. 26. This time around, Keys suspects she may be working with her "strongest" team to date.
Lending an assist this season is Shawn Mendes, whom Keys selected as her celebrity adviser. For more on that partnership, watch below.