This girl is awesome. She's a Russian pianist who does rock/metal covers and improvisations on the piano. She does the arrangements her self, and they are quite good, although I still can't figure out why she doesn't use fifths in her arrangements. (I bring this up because most metal songs use power chords, aka 5chords, which is just root/fifth, as in E/B, or A/E. This is done for practicality, because it is very difficult to change full chord positions at 180 BPM. In her arrangements, however, she uses octaves, not fifths.) I love what she said when someone accused her of speeding up her videos: "I'm a concert pianist; ALL concert pianists play fast."
This is her playing my favorite song, "Tornado of Souls" by Megadeth
If youtube music channels were weapons, The Piano Guys would be the Cobra Attack Helo- the BIG guns. The Piano Guys are a piano store in St. George, and they do -amazing- videos, usually featuring Jon Schmidt and/or Steven Sharp Nelson. Again, double awesome points for being LDS. These guys are among the elite musicians of today, and they have so much fun while doing it.