AQA 7517 4.5.6.8: Musical Instrument Digital Interface (MIDI)
The free BugBot lesson that teach this point, a robot to try it on, and the past-paper questions that test it.
What it covers
Sound is an analogue pressure wave. At GCSE you sampled it, worked out file sizes and found a note from its samples. A level adds the rule that decides how fast you must sample, what goes wrong if you do not, and a completely different way to store music: not the sound itself, but instructions for making it.
- Sampled sound
- The Nyquist theorem
- MIDI
Or do it in the simulator, with tasks that mark themselves
Lessons that teach it
- A7.8 Sound and MIDI Data representation
Sample rate, sample resolution, the Nyquist theorem and aliasing, and MIDI events played on the robot's piezo.
Try it on a robot
The task from A7.8 Sound and MIDI, running here. Change the program and press Run.
The specification is AQA's own document; this page says which of our lessons teach point 4.5.6.8 and is not endorsed by the board.