Musical Typing keyboard - why more than 88 keys?

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mixyguy2
Posts: 417
Joined: Mon Sep 12, 2016 4:54 pm

Musical Typing keyboard - why more than 88 keys?

Post by mixyguy2 » Sat Sep 25, 2021 6:38 am

Just curious.

cactus-head
Posts: 325
Joined: Sat Sep 16, 2017 3:09 pm

Re: Musical Typing keyboard - why more than 88 keys?

Post by cactus-head » Sat Sep 25, 2021 2:00 pm

There are 128 different MIDI note values. 0-127

mixyguy2
Posts: 417
Joined: Mon Sep 12, 2016 4:54 pm

Re: Musical Typing keyboard - why more than 88 keys?

Post by mixyguy2 » Sat Sep 25, 2021 8:34 pm

There are 128 MIDI program values, not note values, which is partly why I ask. Probably missing something obvious, but the light hasn't clicked on yet... :)

cactus-head
Posts: 325
Joined: Sat Sep 16, 2017 3:09 pm

Re: Musical Typing keyboard - why more than 88 keys?

Post by cactus-head » Sat Sep 25, 2021 9:53 pm

No, I mean specifically, there are 128 note values ranging from 0 to 127. I'm not talking about getting into the details of tuning and transposition and the temperment calculation between the steps in playback, I'm talking straight MIDI, a key is pressed, a note value is sent. If you want to call them program values that is fine, but it's confusing when a program value usually refers to the patch or the timbre control.

I'll flipflop between Hexadecimal notation (which is what MIDI is coded in) and decimal. The standard is that note number 60 (decimal) is middle C. You can of course transpose octaves etc, but the range of notes still only can go up to 127 or down to 0.

To play a MIDI note on a device virtual or hardware, a string of data is sent: a Status Byte, The Note Number, and the velocity. The status byte determines whether the note is on or off, the note number is the note number, and the velocity is the velocity.

The beginning of the status byte in HEX has a 9 (note on) or an 8 (note off). It's followed by the zero based channel number. So a Note status for channel 1 would be 90. For channel 2 it would be 91 etc. Next is the note value from 0 to 127. Let's go with the standard and say middle C is note number 60 (3C Hex).

So 90-3c-40 would mean Note On on channel 1, Note number 60 (decimal) with a velocity of 64 (decimal). So the mixcraft virtual keyboard goes all the way down to C -1 which is one octave below C0 (note 12) which is note number 0. And all the way up to G9 which is one octave above most 88 key high G keys which is note number 127. The virtual KB would send those combinations of Status Byte, Note Number and Velocity.

Does that clear up what I mean by 128 note values? Maybe I'm misunderstanding what you are asking

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