The purpose of this post is to test adding video to the post. However, you can also enjoy it.
Hatsune Miku is a software generated 3D cartoon character who is known throughout the world. The reason for her advent is because of VOCALOID, a singing synthesizer application. The company who made this application is called Yamaha Corporation and they created a group of virtual singers with Miku being the main mascot. She is also known as "MiKu Leekspin" because she was twirling a leek in her hand when she first appeared in the promotional animation of the software.
To make the story short, here's the video of the hologram of Miku in a live.
Some fans made thier own hologram of Miku and the video is here: