MIDI protocol was first communication protocol that made it possible for early synthesizers to communicate through a piano keyboard. Before MIDI’s creation, many musicians who used synthesizers or keyboards had to jump around onstage in order to control each and every one. MIDI was created to simplify this process by using only one synthesizer to control the others.
MIDI runs using 8-bit bytes, which are sets of eight binary—or base two—numbers in a row. These numbers can only be 1 or 0, meaning that a particular bit is on or off. In binary’s case, each bit represents the number 2 to a certain power. Because MIDI is 8-bit, the bits will represent the numbers 27, 26, 25, 24, 23, 22, 21, and 20—in that order and from left to right. All possible values for the status byte will be 10000000 or above, in base ten notation this means all values will be 128 or higher. The most significant bit of a data byte is 0. This means that all possible values for the data byte will be 01111111 or below; in base ten notation.
A note on message denotes the note being played, the velocity of that note, and the channel it is being played on. Two data bytes are necessary to complete the notation and both have a range of 0 to 127 for possible base ten values. One data byte determines which note is being played; for example, a value of 60 for this byte represents middle C on a keyboard. The other data byte denotes how loud the note is—or its velocity—with a 0 meaning the note is off.
The controller message constitutes three things. First the controller message on channel 1-16, second, controller number 0-127 and last, controller value 0-27. The status byte is a representation of the controller data. It requires two data byte to complete the controller message.
A patch change message only has one purpose, this determines whether or not a patch or program change is being employed on the synthesizer. The status byte determines what channel the message is being sent to, with a value ranging from 192 to 207 in base ten. The one data byte signifies which patch is employed, with a value from 0 to 127. Nothing else is needed in a patch change message, so only one data byte is necessary.
To turn a MIDI note off, you set the second data byte on a note on message to zero. A MIDI note is on until it receives another note on message with a velocity of zero, which causes it to shut the note off. There is a separate MIDI note off message, but that requires an entirely different status byte connected to the MIDI note number.
The status byte of the note on and the controller messages choose the MIDI channels. In a note on messages, the status byte can then have a value in the range of 10010000 to 159 (1001111) meanwhile the controller status byte can have a value in the range of 176, 10110000 to 191 (10111111). This is basically how MIDI allows you to send many messages at the same time in over 16 different channels.
Midi carries information at a rate of 32,000 bits per second with notes on the message consisting of 30 bits three 8-bit bytes that start and stop bytes for each one. A standard MIDI file contains time stamps for each message that is sent, for example if a note on a message is sent at the very beginning of a MIDI file, the file will contain a 0 on its first time stamp. The 0 denotes what time the message was received, the 144 denotes what channel the note is played on, the 60 denotes which note is being played, and the 96 denotes the velocity of the note. In this instance, the note will keep playing until a separate note on message with a velocity of zero is received, which will turn the note off. Various messages have different numbers of time stamps as well; for example, each time stamp of a controller message represents a change in controller value.
The patch would contain a virtual keyboard that plays a different drum sound for each key that is pressed. The different velocities represent the various volumes of the drums. Each drum would have to last a short few milliseconds before turning off. All notes exist on one channel and the patch would have to be able to send note on messages with velocities of 0 a short period of time after playing each note, in order for the drum noises to not drag out longer than they need to—and longer than they ordinarily would if they were not synthesized sounds.
Every sound can be simplified to a sine wave which can is also plotted on graph. Sound waves or sine waves disturb the air. Most sounds create several sine waves at once which leads them to overlap.and interact sine wave frequencies is what makes any given sound unique.
Equal musical intervals do not possess the same changes in frequency between them, but the ratio of frequencies between them tends to be the same. Notes that are one octave apart operate with a frequency ratio of 2:1. The frequencies rise exponentially, so to the human ear, the difference between 100 and 200 Hz sounds the same as 800 Hz to 1600 Hz, just in a different octave.Notes tend to sound good together if the ratio of their frequencies is equal to the ratio of two small whole numbers; for example, 3 to 2 or 4 to 3. A repeating wave shape of frequency 100 Hz can be created through adding sine waves of 100, 200, 300, 400 Hz. Adding the sine waves in the harmonic series for a particular pitch can create that particular pitch with any possible wave shape.
Sine wave consists of no additional harmonic content. Triangle wave contains additional partials at the odd frequencies, with amplitudes at the inverse of the square of the harmonic number. Sawtooth contains all harmonics, with amplitudes as the inverse of the harmonic number. Square wave contains odd partials with amplitudes at the inverse of the partial number. For a brief example and description of the waveform:
Sine – 1 0 0 0 0 0 0 0, Triangle – 1 0 1/9 0 1/25 0, Square – 1 0 1/3 0 1/5 0, Sawtooth – 1 ½ 1/3 ¼ 1/5 1/6
1) If we embrace the broadest definition of music as being that of “organized sound,” then these works are definitely “music.” How does each piece fulfill or defy your expection of what music should be?
2) What do your guess to be the composer’s intention in creating this work?
3) In what way does the piece communicate to you, as a solitary listerner wearing headphones and listening to it (with less than ideal audio quality, and often without the sense of acoustical space provided by multiple speakers).
#1 John Cage Williams Mix
- I didn’t really consider this piece as music initially. I found the various sounds as distracting rather than listening to it because the sound was not in a organized fashion but rather random.
- I think the composers intention in creating this work was for experimental reasons in trying something new, rather than creating a coherent piece of work.
- This piece did not really communicate to because I could not make sense of it. I had no idea what the sounds were trying to convey.
# 2 Stockhausen “Gesang der Junglinge” (Voices of Children)
- Although I don’t think this piece fits my definition of what music is, I can appreciate the composer trying to mix these sounds in attempt to tell a story.
- I think the composer was trying to tell a story of some sort with the use of children’s voices and sounds.
- This piece really didn’t communicate a coherent message to me but I feel as though the composer is trying to communicate something non the less.
#3 Luciano Berio Ommagio (homage) a Joyce
- This piece also doesn’t fit my expectation of music. I find music to a have some consistency in the pattern, which I felt this piece was missing.
- The composer in my opinion, like the previous composer, is trying to convey a story with the use of voice and looped sounds.
- This piece also did not communicate a coherent message or pattern which I was able to follow.
#4 Milton Babbitt Ensembles for Synthesizer
- Although this did not meet my expectation of music, I appreciate it more than the other pieces because of our exposure to pd. in class.
- I think the composer was trying to show how to combine different sounds and frequencies to create a patterned sound structure of some sort.
- This piece communicated to me because it caught my attention by the different sounds at different levels the composer employed in the piece.
#5 Morton Subotnick Silver Apples of the Moon
- This piece was interesting because unlike the previous pieces I was able to follow its pattern a lot more.
- The composer intention in creating this work is was to create a piece of music using electric music methods.
- This piece was actually distracting in the sense that it drew me in but I couldn’t make sense of it.
#6 Alvin Lucier I am Sitting in a Room
- This piece was interesting in that, the sound and voices seem to gradually change but yet keep the same underlying tone.
- I think the composers intention in creating this piece was to play around with the idea of playing his speech and turn it into some sort of music.
- This piece communicated more then the other pieces in my opinion because the author actually talked and explained his intention in creating this piece.
#7 Terry Riley A Rainbow in Curved Air
- This piece fit my expectation of what music is. I found the sounds and rhyme easy to follow more so than the other pieces.
- I think the composer’s intention was to make different sounds at different levels of volume sound smooth and coherent.
- This piece reminded a lot of our work with pd. and some the sounds I heard in class.
#8 Steve Reich Come Out
- This piece fits my expectation of what music is because of the patterns throughout the piece.
- I think the authors intention was to create music with the repeation of a voice.
- This piece communicated how a voice playing over and over can actually turn into a catchy beat.
#9 Brian Eno Atmospheres
- This piece fits my definition of music because you can hear pattern to it and even dome string music.
- I think the composers intention in this piece was to use different sounds to coherently put forth music for listeners.
#10 Beatles Tomorrow Never Knows (1966)
- This piece fits my defintion of what music is. I do not listen to his genre but i actually enjoyed this piece.
- I fell as though the composers might have been trying to experiment with this sound. I feel like they were trying to combine little sounds to convey a bigger message in a way.
- This piece communicated a coherent song to me. I found the different sounds throughout this piece enjoyable.
#11 Afrika Bambaataa Looking for the Perfect Beat
- This piece definitely fits my definition of what music is. I found this very similar to a lot of current structures in music especially hip hop music.
I think the composer was trying to convey different melody and rhythm through the song so the listeners could enjoy it.
I think this piece was very easy to listen to and was catchy. It caught my attention and forced me into the song because of the rhythm and melody.
First assignment. music with computers pd1