The FL is in some sort of abusive marriage and her husband locks her up in a room where she dies I guess. When she wakes up she's isekai-ed into some historical era. The ML visits some kind of brothel (?) and the main girl there has a crush on him so she sees the FL as competition. To mock the FL, she holds a kind of music competition where they have to play some kind of historical string instrument and the FL surprises everyone with her music. I think the FL was actually a music composer in her previous life

Did you find the name? It seems interesting

Hi) My best guess this is title called You can’t kill me: The secret bride of the black wolf. p.s. Had to register eventually after more than 10 years of unauthorized raids just to post this comment 🤣

thank you sooo much!! i had completely forgotten about this and logged in just now randomly. sorry for this super late reply but i'm really grateful ♡♡♡

heyy! so sorry for this extremely late reply, but as Musumezakari answered, it is : You Can’t Kill Me: The Secret Bride of the Black Wolf