Baby's Emotional Reaction to Mom's Singing Will Move You to Tears

If you don't have any tissues handy, you might want to get some right now.

Why? Well, the latest video to light up the Internet has caused an emotional reaction in viewers across the world.

In the video, a mother can be heard telling her young daughter that she was going to sing her a song.

"Let me know how you feel about the song, OK?" the woman said, before launching into Rod Stewart's poignant hit, "My Heart Can't Tell You No."

The baby's reactions are immediate: The child, sitting in her high chair, appears to experience a wide range of emotions. At first she beams and looks intently at her mother, and then her expression changes. She scrunches up her face and her eyes fill with tears that run down her cheeks, but she doesn't cry out. She even smiles while the tears continue to flow.

When the woman finishes singing, she addresses her daughter's reaction: "Oh, you feel the pain in the song, yeah honey … oh, you're crying, monkey. OK, mommy's done. OK, it's just a song. It's just a song, honey," she said, and the baby starts to laugh.

"We know that babies mirror facial expressions and by nine or ten months of age they can distinguish between a happy face and a sad face," said Dr. Jennifer Ashton, ABC News' Senior Medical Contributor. "We also know that this mom did sing to this baby multiple times and always had this reaction."

Titled "Emotional baby! Too cute!," the video had been viewed more than 2.6 million times as of Tuesday night.

It was recorded Aug. 1 and uploaded to YouTube Oct. 18 when the baby, Marie-Lynne Leroux, was 10 months old.

The girl's mother, Amanda Leroux, of Ontario, Canada, said the song gets her daughter every time, according to the website Storyful.

"No one can explain why, not even I," the girl's mother told Storyful. "I can sing any other song and do not get the same reaction from her. It's (too) adorable to keep all to ourselves."

Leroux told Canada's TVA that she noticed her daughter's strong emotional reactions to her singing when the child was about 8 months old. When she would sing happy songs, Marie-Lynne would smile, and sad songs would produce tears, especially the Stewart classic that Leroux sings in the video.