Physics 1251 The Science and Technology of Musical Sound

1. Physics 1251The Science and Technology of Musical Sound Unit 4 Session 41 MWF MIDI

2. Physics 1251 Unit 4 Session 41 MIDI What is the maximum frequency that can be represented by data that was digitized at a sampling rate of 10 kHz? By the Nyquist Criterion: fmax = ½ R Or 5 kHz.

3. Physics 1251 Unit 4 Session 41 MIDI 1′ Lecture: • MIDI is the acronym for “Musical Instrument Digital Interface.” • MIDI is a control protocol that uses binary codes to remotely control electronic musical instruments. • MIDI uses a current loop to communicate in which current flowing means “0” and no current means “1.” • The Electronic wind instrument (EWI), Electronic Valve Instrument (EVI) and Electronic String Instrument (ESI) use MIDI for control.

4. Physics 1251 Unit 4 Session 41 MIDI 80/20Digitization is the process of converting a waveform into a series of binary numbers that represent the amplitude of the signal at equal intervals of time. Analog Waveform Digitized Waveform Pressure [1000]2[0100]2[0010]2[0001]2 Binary Coded Data

5. Physics 1251 Unit 4 Session 41 MIDI 80/20MIDI (1982) sends, not a digitized wave form, but rather a binary coded performance message to control electronic instruments (synthesizers). Master MIDI Out Slave

6. Physics 1251 Unit 4 Session 41 MIDI MIDI—Physical: A five pin connector labeled “MIDI Out,” “MIDI In,” or “MIDI Thru.” Communication is via current. MIDI Out MIDI In Communication via current:current = 0, no current = 1

7. Physics 1251 Unit 4 Session 41 MIDI MIDI—Physical: A five pin connector labeled “MIDI Out,” “MIDI In,” or “MIDI Thru.” Communication is via current.

8. Physics 1251 Unit 4 Session 41 MIDI MIDI Physical: A MIDI chain can be assembled of up to 64 channels [0000]2 to [1111]2. MIDI Out MIDI Thru Channel 00 01 02 03 04

9. Physics 1251 Unit 4 Session 41 MIDI MIDI Coding: A MIDI command is a word of three 8-bit bytes—status and 2 data bytes. Example: Status Data Data [10010100] [00111100] [011111111]: {09, 04} {060} {255} Note on, C4 Speed 255,(hardest) Channel 04 100101 00 001111 00 01111 1111

10. Physics 1251 Unit 4 Session 41 MIDI 80/20A MIDI command is a binary code that follows a prescribed syntax and grammar. Example: Status Data Data [10000100] [00111100] [011111111]: {08, 04} {060} {xxx} Note off, C4 Irrelevant Channel 04 100001 00 001111 00 01111 1111

11. Physics 1251 Unit 4 Session 41 MIDI MIDI Instruments: Electronic Wind Instrument (EWI) MIDI signals: Note, pressure, lip

12. Physics 1251 Unit 4 Session 41 MIDI MIDI Instruments: Electronic Valve Instrument (EVI)

13. Physics 1251 Unit 4 Session 41 MIDI MIDI Instruments: Electronic String Instrument (ESI) Janos Warren Bond—Electric Strad

14. Physics 1251 Unit 4 Session 41 MIDI MIDI Instruments: Gesture Instruments (GI)h “The Glove” Prof. Butch Rovan

15. Physics 1251 Unit 4 Session 41 MIDI Summary: • MIDI is the acronym for “Musical Instrument Digital Interface.” • MIDI is a control protocol that uses binary codes to remotely control electronic musical instruments, where a current loop is used to communicate • The Electronic wind instrument (EWI), Electronic Valve Instrument (EVI) and Electronic String Instrument (ESI) use MIDI for control.