Online music jam/Global Metronome

A global metronome can be used for to keep a the musicians in sync. The basic idea is to use the Network Time Protocol (NTP) in an WebApp that runs in a browser of your choice on Linux, Windows, MacOSX, Android, iOS, ... that creates a visual beat (e.g. 120 bpm - beats per minutes) with a joint offset from a timestamp shared between the musisians e.g. with a JSON file loaded into the WebApp.

Learning Tasks

 * Online jamming e.g. with OpenSource Jamulus has the main challenges to keep the latency of the submitted tracks as low as possible. Nevertheless even minimal latency can slow done the Beats Per Minute e.g. from 120bpm to 100bpm, because musicians tend to adapt their own tempo to the other musicians to keep in sync. This is a good approach in general to keep a band in sync playing live together. But technical latency could slow down the tempo of the whole band step by step. Explain how a visual or click based metronome could support that loss of tempo and identify the challenges and constraints for the musicians even if a global metronome is used (e.g. the song has different tempi by default or slows down or speed up as wanted feature of the performance, ...)
 * Test the Global Metronome during a online jam or rehearal, start the global metronome at different times stop and restart the metronome. What can be observed? Start to could silently in the given tempo and stop the global metronome and restart after a short period of time. Could you keep the pace without the global metronome?

Submodules

 * Test the global metronome for online jam or music rehearsal at https://niebert.github.io/globalmetronome - the global metronome was implemented for this Wikiversity learning resource as AppLSAC (GitHub repository globalmetronome.
 * Mathematical Arithmetics for a Global Metronome

Programming Task
If you want to create a web based global metronome use for example the OpenSource WebApp metronome by Scott Hudson. The basic idea of responsive webapps is that you can start the global metronome with your smartphone and use the metronome for online rehearsal of a choir. A visual metronome is useful to keep the pace without clicks that are disturbing the musicians.