Beyoncé's song "Deja Vu" is in the key of F♯ minor.
The song features a strong minor key feel throughout, with the melody and harmonies revolving around the F♯ minor chord. This key choice contributes to the song's overall mood of longing and nostalgia, which aligns with the themes of the lyrics.
You can find the song's key signature in sheet music or online resources, such as music theory websites or music notation software.
