Lady Gaga must have had another commitment.

This explains why "Real Housewives of Atlanta" star Kim Zolciak will guest judge the fantastical dos on tonight's finale of Oxygen's reality competition "Hair Battle Spectacular."

The wig-loving Housewife also stops by to advise the finalists in the over-the-top hair design competition. The contenders, Tsunami, Minasta (she really is a minister), and Fingaz will take Zolciak's big blonde advice as they contemplate designs for complete hair outfits in the show's final Glam Slam.

Seriously, with that kind of meaty task, it's a wonder Gaga didn't want in.

Meanwhile, the final dramatic hair designs must express the stages of a romantic relationship.

So, of course, the question will be which designs make the judges fall in love! The jurists include Atlanta hairstylist (and Zolciak pal)) Derek J, stylist Lindsay Albanese, and host Brooke Burns.

The winner of "Hair Battle Spectacular" gets a $100,000 prize and (we hope) the chance to resume using their real name, not the one the show bestowed upon them for drama's sake.

The "Hair Battle Spectacular" begins tonight at 10 p.m. on Oxygen.

In other reality news, check out our chat with Zolciak's always buff "Atlanta" cast mate Sheree Whitfield.