Introduction to MIDI and Computer Music: Quiz 1 Review

Quiz 1 Review

Make sure you understand the following concepts and terms, which are drawn from the lecture PowerPoint slides (supplemented by optional readings in Pellman, ch. 5-6), from your work with the Korg synthesizer and Digital Performer sequencer software, and from your in-class notes.

The information and links in brackets tell you something about the answers or where to find them. There is much more information about MIDI in the IU CECM online textbook.

The MIDI system

MIDI connections (OUT, IN, THRU) [midi_setup.ppt]
Star and daisy-chain networks (of MIDI devices). What are the pros and cons of each? [midi_setup.ppt]
Multi-port MIDI interface [midi_setup.ppt]
Re-channelizing MIDI messages [local_control.ppt and Understanding Local Control]
Local control [local_control.ppt and Understanding Local Control]
MIDI data rate (bits per second) [midi_lowlevel.ppt]
MIDI messages consist of a status byte and one or more data bytes.
What two pieces of information does the status byte usually convey? [midi_lowlevel.ppt]
Channel voice messages
1. Note on
2. Note off
3. Program change
4. Pitch bend
5. Control change
6. Channel (or monophonic) pressure (or aftertouch)
7. Key (or polyphonic) pressure (or aftertouch)
What is the purpose of each of these types of message?
What specific data does each transmit?
What range of values is used for the various pieces of data?
[midi_lowlevel.ppt]
What effect does varying note-on velocity usually have on a sound?
[Higher velociy usually makes the sound louder and brighter.]
Controller numbers for:
1. modulation wheel (JS+Y on Triton)
2. breath controller (JS-Y on Triton)
3. volume
4. pan
5. sustain pedal
[controllers.ppt]
How does the pan controller message work? For example, what values specify hard-left, center and hard-right speaker locations?
[Play with the pan knob in the DP Mixing Board to figure this out: watch the numerical value readout while you turn the knob to different positions.]
Continuous vs. switch controller messages [controllers.ppt]
Most MIDI messages have a range of values from 0 to 127. That means they have 128 steps of resolution. [midi_lowlevel.ppt]
- How many steps of resolution do pitch bend messages have?
- Why does pitch bend require more resolution than other kinds of MIDI message?
What is a MIDI Bank Select controller message used for? Why is its use necessary with recent synthesizers? [midi_lowlevel.ppt]

Digital Performer (and other sequencers)

Ticks (How many per quarter note in Digital Performer?) [quantization.ppt]
Quantization [quantization.ppt]
Overdub
[A sequencer mode that allows you to record onto a track without erasing existing MIDI data; the new data merges with the old.]
Automation
[The term given to dynamic changes of volume, pan, mute and effect settings in a recording console or software mixer, such as the one found in Digital Performer.]
Conductor track
[The sequencer track that holds only changes in tempo or meter.]