[LAD] successive note on midi events

Ralf Mardorf ralf.mardorf at alice-dsl.net
Mon Apr 12 06:15:08 UTC 2010

James Morris wrote:
> On Mon, April 12, 2010 00:38, James Morris wrote:
>> Hi,
>> I'm pretty sure I've seen this dealt with on the list before, but can't
>> find it.
>> With the program I'm fumbling around trying to create, it will be possible
>> for successive note on events for the same pitch to occur without note off
>> events intervening.
>> Does the MIDI spec allow such things?
> Sorry to answer myself so soon...
> I guess it is allowed. The simplest case being a sequencer outputting to
> the same channel and port as a keyboard player. Nothing can prevent this -
> right?

Regularly you shouldn't connect two output devices to one input device 
without using a MIDI merge box.
Anyway, the receiving MIDI equipment might be able to handle successive 
note on events for the same note number, while they were received 
without note off events between those notes, but it's not good to send 
no note off events, resp. note on events withe a velocity value of 0. 
Drumsamplers and monophonic synth might be able to handle this, but for 
polyphonic synth you could run into trouble.

> And there's no way in the world that missing note-offs could be added in,
> in a fashion guaranteed to cover all possible permutations of connections,
> or without delaying the note-on which implies a missing note-off.


> James.
>> The bash-script prototype of the program did this, and, I believe, the
>> soft-synths used, acted appropriately - that is, re-triggered the notes.
>> So I guess the question is, does it make any difference if I add-in the
>> note-off events - which, thinking about it, is going to be tricky because,
>> basically, although the program is sequencing, it will be real time and is
>> not psychic!
>> Cheers,
>> James.

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