LS-R economically viable. The need for the disc to be meticulously constructed from many layers of different materials, and the need for the drive to be able to electrically address each layer specifically, may make this solution too expensive for commercialization. In the next generation LS-R may compete with other next-generation optical disc format such as the Holographic versatile disc and Protein-coated disc formats. LS-R LS-R, or the Layer-Selection-Type Recordable Optical Disk, is the term coined by Hitachi in 2003 for a next-generation optical disc technology which allows much larger data storage densities than DVD, HD DVD or Blu-ray Disc, by
What Is and What Should Never Be and What Should Never Be" was performed live at Led Zeppelin concerts between 1969 and 1973. A live version taken from a performance at the Royal Albert Hall in 1970 can be seen on the "Led Zeppelin DVD". Another was included on disc two of the live triple album "How The West Was Won". Two more versions were included in BBC Sessions. What Is and What Should Never Be "What Is and What Should Never Be" is a song by English rock band Led Zeppelin. It was written by Jimmy Page and Robert Plant and was included as the second