Cloud the bottom of the hierarchy. Clouds in the troposphere assume five physical forms based on structure and process of formation. These forms are commonly used for the purpose of satellite analysis. They are given below in approximate ascending order of instability or convective activity. "Non-convective" stratiform clouds appear in "stable" airmass conditions and, in general, have flat sheet-like structures that can form at any altitude in the troposphere. The stratiform group is divided by altitude range into the genera cirrostratus (high-level), altostratus (mid-level), stratus (low-level), and nimbostratus (multi-level). Fog is commonly considered a surface-based cloud layer. The fog may form
Digital sheet music more on the practice and consumption side of music learning. These latter cloud-based applications integrate audio-output such as playback with a variety of tempi (speeds) and with different instrumentation for multi-part scores and make the viewing and playing more interactive by adding personal annotations, automatic page turning, or set lists. Overall, four factors appear to facilitate digital sheet reading: computer, content, containers and controllers (Hugh, 2013): Digital sheet music Digital sheet music is technology for representing and displaying sheet music in a computer-readable format. With the emergence of several technological innovations, sheet music evolved in several stages into what was