Igneous rocks are classified according to their texture and composition. Composition refers to both the types of minerals within a rock and the overall chemical makeup of the rock (the two are obviously related). Texture refers to the size and arrangement of the minerals or grains that make up a rock.
Pentatonix (or PTX) is an American a cappella group consisting of five vocalists originating from Arlington, Texas.entatonix began with three friends who grew up together and were schoolmates at Martin High School in Arlington, Texas: Kirstin Kirstie Maldonado (born May 16, 1992), Mitch Grassi (born July 24, 1992), and Scott Hoying (born September 17, 1991).
Pentatonix performed two shows in Rochester, New York, on December 11, 2011 in support of the University of Rochester YellowJackets' United We Sing Kenya project. The event, which also featured all-female octet Delilah, was hosted by the YellowJackets at Kodak Hall at the university's Eastman Theatre.