code: func ChannelAfterTouch(channel, vel int) *Event {
  	return &Event{
  		MsgChan:  uint8(channel),
  		MsgType:  uint8(EventByteMap["ChannelAfterTouch"]),
  		Pressure: uint8(vel),
  	}
  }
docs: // ChannelAfterTouch is a global aftertouch with a value from 0 to 127