Anytime an artist goes through a breakup and then releases an album soon after, there's a good chance that at least one of the songs on the album will contain some sort of insight about the relationship. I've been through a number of the tracks already, and you know I have to ask — is Lady Gaga's song "Diamond Heart" about Taylor Kinney? She hasn't commented on that particular song's inspiration, so we don't have official confirmation. However, there are some clues suggesting that Gaga might have been struck by some Kin-spiration — get it? — while writing "Diamond Heart".
The biggest clue is in the song title itself, which seems to reference Gaga's engagement ring from Kinney: a heart-shaped diamond. I see you, girl. Gaga and Kinney began dating in 2011, after meeting on the set of the former's music video for "Yoü and I". They got engaged in February 2015, with a distinctive piece of jewelry that Gaga documented on Instagram with the caption, "He gave me his heart on Valentine's Day, and I said YES!"
Unless my eyes deceive me, that is a diamond heart right there. The fact that Gaga herself called it out in the caption makes me think that the title of this song couldn't possibly be random. She and Kinney broke off their engagement in July 2016, just three months before Joanne dropped. Even though it's already been questioned whether "Perfect Illusion" and "Million Reasons" are about Kinney, I wouldn't be surprised if multiple songs have references to their relationship, both good and bad.
The first verse and pre-chorus of "Diamond Heart" are discussing other elements of Gaga's past, like her sexual assault and how she got her start in go-go dancing. But the chorus itself seems to be about Kinney:
Young, wild, American
C'mon baby, do you have a girlfriend?
Rain on me a million
I'm not flawless, but I got a diamond heart
According to Rap Genius, the line about having a girlfriend is a reference to the fact that Kinney did in fact have a girlfriend when he and Gaga first met. This is something Gaga confirmed in a 2015 interview with The Daily Mail Online, saying, "We always thought each other was attractive, I was in a relationship at the time, he was too. Then we both broke up and were both single". Then later, in the bridge, Gaga seems to predict the end of her own relationship, even as she has the diamond heart on her finger, singing:
Good thing I know what I'm worth
Want a good thing, put the money down first
Better get a good look baby
'Cause soon I'm breaking out of here
She seems to be suggesting that she knows what she's worth, and it's more than just a diamond heart; without your full heart and emotions invested as well, a diamond is worthless to her. But she ends the song with a reminder that she still has that "diamond heart," which, since she isn't wearing her ring anymore, suggests to me that she's saying she has an unbreakable core, as hard as any diamond, but still a heart. She isn't closed off, but you can't hurt her.