Christina Aguilera performed Etta James' signature hit 'At Last' at the legendary singer's funeral on Saturday, Jan. 28, and she nailed all the massive notes. Her voice made the hair on the back of our necks stand up.

However, there was chatter about a mysterious liquid of some sort running down her leg during the performance, as video footage began to circulate the web. Xtina is even seen addressing the problem, and dabbing at her leg while performing. So what was it? No one knows and does it really matter?

Here's why we think it is of little importance:

Aguilera, dressed in a black skirt suit, which showed off her legs and was low cut enough to show off her ample bust, and killer heels, was particularly passionate and understandably emotional about this performance, given her love for James. Aguilera, wearing a cross around her neck, even prefaced her perf by saying, "She was the one that cut right to my soul and spoke to me. So tonight, Etta, this song’s for you," as her voice broke ever so slightly. Her performance was flawless, a far cry from last February's much-publicized national anthem flub. Etta would have been proud.

Even so, the cameras caught some sort of liquid dripping down the singer's shapely legs during the performance, at around 3:50 in the video below. That's when we see Xtina rub her legs together, as if to wipe the substance away. What was it? We don't know, but speculation abounded online that it may have been menstrual blood. That doesn't seem likely or plausible. Women known their internal clocks and cycles, and are prepared.

Maybe it's a lotion, body oil or some other cosmetic that she used before getting dressed? Again, that's also a long shot.

It's not known and it's highly unlikely that the singer will issue a statement or address the matter, which could be embarrassing. It's best for her to move on and it'll be forgotten in a few weeks. It's just a shame that Aguilera delivered such an earth-shattering, mistake-proof version of the song in a very public forum yet the substance running down her leg is getting the most attention.

Watch Christina Aguilera Perform 'At Last'