Kali Uchis and Mariah The Scientist are buds. In July, Uchis guested on Mariah’s “Is It A Crime,” from her album Hearts Sold Separately. Today (October 3), they released a video for the track.
Also today, the pair offered another new collaboration. This time, it’s Mariah guesting on Kali’s song, from Uchis’ deluxe album Sincerely: P.S. that’s out now. The dreamy track sees the two singing about keeping their word.
Uchis previously noted that the original Sincerely, album was inspired by a “life-altering event,” revealing, “The album is about the complexities of life and finding ways to find joy in life despite the world. Finding ways to appreciate every moment and not take life for granted. Treat every day special. It’s my most existential and honest work. It’s definitely the most beautiful body of work to me, and it’s going to be, for me, the most meaningful and impactful.”
Listen to “Pretty Promises” above.
Kali Uchis’ Sincerely: P.S. Album Cover Artwork

Kali Uchis’ Sincerely: P.S. Tracklist
1. “Heaven Is a Home…”
2. “Sugar! Honey! Love!”
3. “Lose My Cool,”
4. “It’s Just Us”
5. “Territorial”
6. “Silk Lingerie,”
7. “Fall Apart,”
8. “All I Can Say”
9. “Daggers!”
10. “For: You”
11. “Angels All Around Me…”
12. “Breeze!”
13. “Sunshine & Rain…”
14. “ILYSMIH”
15. “Cry about it!” Feat. Ravyn Lenae
16. “Whispers of the Wind…”
17. “Pretty Promises,” Feat. Mariah the Scientist
18. “Cherry on Top”
19. “All of the Good”
Kali Uchis’ 2025 Tour Dates
10/23 — Highland, CA @ Yaamava Resort & Casino
Sincerely: P.S. is out now via Capitol. Find more information here.