Bette Davis movie "Dead Ringer"--Band in nightclub

In this movie, made in 1964, Davis plays two twin sisters, one of whom runs a bar. Through most of the bar scenes a bluesy instrumental band is heard which sounds an awful lot like Booker T. & the M.G.'s. However, they’re not credited, and I couldn’t find anything about this possibility either in or

Does anyone know the truth of this?

According to, Andre’ Previn is credited with the music, so he could have written the music for the band… But I don’t know, haven’t yet seen the film. Maybe Eve has, if she shows up here…