Natural fiber Keratin is a structural protein located at the hard surfaces in many vertebrates. Keratin has two forms, α-keratin and β-keratin and are used by different classes of animals. The naming convention for proteins follows that for keratin, alpha keratin is helical and beta keratin is sheet like. Alpha keratin is found in mammalian hair, skin, nails, horn and quills, while beta keratin can be found in avian and reptilian species in scales, feathers, and beaks. The two different structures of keratin have dissimilar mechanical properties, as seen in their dissimilar applications. The relative alignment of the keratin fibrils has a
Hair (Lady Gaga song) about having a good time." Matthew Perpetua from "Rolling Stone" called it a mixture of yearning romantic melodrama of "We Belong" with the hard industrial metal edge of Broken-era Nine Inch Nails. Greg Kot of the "Chicago Tribune" felt that Gaga's vocals are Auto-Tuned throughout the song. The lyrics of "Hair" talk about embracing one's hairstyle as the ultimate expression of their identity, hence it ends with Gaga triumphantly declaring "I am my hair!" at the end of the final chorus. "Hair" has received mostly positive reviews. An hour before starting the final leg of The Monster Ball Tour, Gaga