Reddit reviews MIDI For The Professional

this is how i got started, and it is a fantastic and easy-to-read book. Also, it's cheap and easy to find. I didn't even finish it, i just read the first few chapters and now I have a room full of synths being controlled via one master weighted key controller and a box with a bunch of knobs and faders that send midi. I could put all of my synths in a closet if i wanted, and just use my midi controllers to edit them.

there's really only a few things you need to know. Binary and hex notation are not so difficult once you get the gist. Essentially, there are a handful of different messages you need to know about.


Here's a quick run through midi:

• all midi messages are passed as bytes
  
  
• a byte is 8 bits, or eight 1's or 0's in a row
  
  
• a byte just represents a number, where the highest possible number in any byte is the integer 255. in hex, this looks like FF
  
  
• hex notation is written like this: 0xFF, where the 0x denotes that the following number is in hexadecimal.
  
  
• hex is easy if you think of it like this: the number 10 (in decimal) is represented by A (in hex), 11 by B, 12 by C, 13 by D, 14 by E, and 15 by F. For example, in hex, 0x09 + 0x01 = 0x0A and 0x0F + 0x01 = 0x10
  I understand that it can be mind-bending, but the takeaway here is that instead of 'carrying the one' when you add 9+1 in decimal, you only 'carry the one' when you add 0xF + 1, and this is because, in decimal, we dont have a single digit to represent the number 10, and likewise, we don't have a single digit that represents 16.
  
  
• a midi message consists of a status and data portion. for example, when you hit a note on your keyboard, three bytes will be generated, and these three bytes together is a message. the first byte says that the message is a note on, the second byte indicates which note you hit, and the third byte indicates how hard you hit the note (which is known as velocity)
  
  
• a status byte will always be greater than or equal to 128, and the data bytes will never be greater than 127.
  
  
• a midi message can be a single byte, two bytes in a row, three bytes in a row, or many bytes in a row (depending on the device). for example, a clock pulse is only one byte, a note on is three bytes, and a control change (your pitch bend or mod wheel) can be three bytes (or the status followed by many data bytes until you stop moving it)
  
  
• All devices that support midi will have an implementation in the back of the manual
  
  
• There are two main types of midi message, Channel and System messages. Channel messages happen when you play your instrument, and these events happen on a specific channel. The main takeaway here is that synths only respond to channel messages which are on their channel (like if you had three synths all chained, each on a seperate channel, and you want to play the first synth on channel 1, the second on channel 2, etc.). System messages are more for timing and syncronization, and will generally always be acknowledged if the device recieves the message (like clock pulses, start/stop, etc.).
  
  
• CAVEAT:System Exclusive messages fall under System messages, but only one specific, or one type of, device will respond to these messages.
  
  
• System Exclusive messages are, surprisingly, exclusive to specific devices. these types of messages are generally more than 3 bytes long, they generally look like this: Start system exclusive --> a bunch of bytes to do something --> stop system exclusive
  
  
  ** note: if you're thinking "hexadecimal means sixteen! but 0x0F means fifteen! what's the deal?!" this is because the first digit is zero, so there really are 16 possible single-digit numbers we can represent. the same goes for decimal, where zero is our tenth (or first) number.
  hope this helps