Season one was filmed in New York entirely during the COVID-19 pandemic.
The show couldn't get Dolly Parton to cameo because it was short-noticed and in the middle of the COVID pandemic, so they needed someone to play Dolly who was already tested and available, which was Tina Fey.
Alf Musik, portrayed by Stephen Colbert, is emulating the real Swedish songwriter, Max Martin, both in physical appearance and songwriting prowess. Martin wrote hits for/with Britney Spears, Backstreet Boys, *NSYNC, Taylor Swift, Katy Perry, Ariana Grande, and more.
Executive producer Tina Fey previously collaborated with Paula Pell in 30 Rock (2006), Sisters (2015) and Wine Country (2019), with Renée Elise Goldsberry also in Sisters, and with Busy Philipps in Unbreakable Kimmy Schmidt (2015) and Busy Tonight (2018).