Virtual pop star Hatsune Miku stopped by David Letterman's The Late Show last night to promote an art exhibit in New York featuring her merchandise, and it's pretty easy to tell Letterman had no clue what was happening.

For those not in the know, Miku is a vocaloid, a fancy word for a synthesizer that sings music. She is represented at concerts and appearances via a hologram of a young pop star with long, turquoise pony tails. Watch her Letterman performance of "Sharing the World" below.

To his credit (despite it being obvious how ridiculous he thought the whole situation was) Letterman keeps his cool. He introduces Miku like any real performer and thanks her and the band for appearing. You can tell he is ready for her to disappear sooner rather than later, though. Once she finally does, Letterman's parting comments are what really make the entire situation priceless.

"It's like being on Willie Nelson's bus," the longtime late night host said.

While Letterman, and most of America for that matter, might not understand Miku's appeal, she is a phenomenon in her home country of Japan. Aside from bringing in thousands of fans to concerts and performances, Miku has also endorsed some big name companies and products in the country, from Domino's Pizza to Google's Chrome web browser. She will also be appearing in two video games coming stateside in the next year.

Her art exhibit, called "Universal Positivity," is now open in New York until Oct. 19 at Wallplay. In addition to artwork and merchandise featuring Miku's likeness, the exhibit will also include virtual performances from Miku and her band.

At the end of the day, appearing on any late night show is good exposure for the vocaloid owned by Japanese company Crypton. But with Letterman looking so perplexed over the whole matter, maybe Miku should have gone with Jimmy Fallon instead.