Joaquin Phoenix is opening up about the making of Joker: Folie à Deux, particularly on how its love story is driven by music, as well as his working relationship with Todd Phillips and when they could work together again.

Phoenix, returning as Arthur Fleck/The Joker, told Blavity’s Shadow and Act in a recent interview ahead of the film’s release that while a second film wasn’t necessarily something that he and Phillips thought would be a given, he was very eager to continuing on with the character and though that there was more story to be told. Phoenix is joined in this sequel by Lady Gaga as Lee Quinzel aka Harley Quinn.

“While we were still making the first film, I was sad to know that it was coming to an end and I wanted to continue working with Todd,” he told us. “And I thought there was more to do with this character. I was like, ‘Todd, we could put this character in any situation and it potentially is interesting.’ So. I had a movie posters made of 10 different classic films, and I photoshopped Joker’s face onto those posters. So it was One Flew Over Cuckoo’s Nest and The Godfather and Yentl. And I made a poster that had 10 posters on it, and I gave it to him, I signed it, and I said, ‘What are we doing next?'”

While the film may not necessarily definitely as a textbook musical per se, the musical moments in the film are important, which is something that Lady Gaga noted in her interview with us, stating that they “spent a lot of time talking about the voice, and for my character, I wanted to find a voice for her that would be uniquely hers.”

Phoenix notes how the film’s music moments, which are likened to the rhythmic nature of the first film, also drive the moment of love that Arthur finds himself in after meeting Lee.

“It felt like it was a natural extension of the first film and what was established in the first film of music and dance, and something about Arthur and Joker that is kind of really is Joker– it’s performative,” he said. “So it seemed like it was a natural progression. Also, I don’t know how to say this without sounding just like lame [laughs], but when you think about a song, so many of our songs are love songs because there’s this moment when you fall in love…you have this desire to sing out [and] just words in and of themselves aren’t enough. That melody along with it feels necessary. You think about just birds singing and there’s something just alive about it in a way. [Arthur is] largely silent when we meet him…through the first 10 minutes or so, he almost doesn’t say anything. And then he sees Lee, and it’s like this moment of coming alive, and then he leaves that meeting and he just bursts forth in songs.”

Viewers also meet perhaps more dimensions to the Arthur that we met in the first film, and Phoenix agrees with this sentiment.

“It felt like you wanted him to be more inscrutable in the first film,” he explained. “There’s something about the mystery of him that would be make you lean in and make it something interesting about the character. I think in some ways, this film is examining what is our true character and what is the character that we present to the world. That’s something that he wanted so desperately in the first film, just to be seen and heard, and he felt like the only way that that happened was when he created this character and this new part of himself emerged. In in this film, when he experiences romance and love, suddenly there’s something about love that makes you want to be as honest and authentic as possible. And when the person that you love, if they love the part of you that maybe is not the most authentic part of you, would really give you kind of pause and be confusing. I think in some ways this romance makes Arthur kind of reexamine himself and really the events of the first film and his actions and asks really whether redemption is possible him.”

Also, this is proving to be another successful Phillips-Phoenix collaboration, and the latter is already eager for more, adding “We’ve found a really unique way of working together [that] I think we both enjoy. Part of it is there’s really never any guarantee of whether the world is going to respond to what you’re doing. The only guarantee you have is, ‘What is the process like?’ And I know with Todd that it’s going to be a fulfilling process for me. I don’t know if anyone else is going to like it. I don’t know if it’s going to be meaningful in any way, but for me, creatively, it’s just an incredible process. So yeah, I’m game.”

The film hits theaters Oct. 4.