Parent series Grey's Anatomy aired its own musical - season seven's 'Song Beneath the Song' - in March 2011.
"The musical talent on Private Practice is equally stunning [as Grey's]," Rhimes told TV Guide. "Kate Walsh (Addison Montgomery) can sing a little bit - but she doesn't want to - and I'm very curious to see what's going on with Benjamin Bratt's (Jake Reilly) talents."
Private Practice star Walsh recently indicated that she will leave the series at the conclusion of its sixth season, which premieres on September 25 on ABC.
Showrunner Rhimes has described the medical drama's next run as "a no-holds-barred, all-bets-off season".
"[There'll be] a death, some babies, a likely return of a favourite and there could possibly be a wedding," she confirmed.
> ABC boss on Grey's Anatomy: 'I think you've seen the major exits'
> Private Practice Caterina Scorsone gives birth to baby girl
Watch a promo for the Private Practice season five finale below: