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Topic: What does a velocity override of zero mean on dynamics? (Read 6195 times) previous topic - next topic

What does a velocity override of zero mean on dynamics?

I've read a number of threads on the subject of dynamics, velocity and volume, but one thing escapes me.

I've been trying to dynamicly (in a repeat loop) mute and unmute notes on a staff without effecting other staves using the same channel (see my too numerous posts in the newsgroup).  It was suggested that I use the velocity override on a dynamic marker to do this, but I found that the note still sounds even if the velocity is set to zero.

Is this a general MIDI (no pun intended) rule, or a quirk of the SB-Live sound card?  What DOES velocity of zero mean?

Cyril

Re: What does a velocity override of zero mean on dynamics?

Reply #1 –
Cyril,

This question should be directed to NoteWorthy Online.
It must be part of the implementation of dynamics in NWC.

My understanding of MIDI dynamic levels involves:-

Volume - Controller 7 sets the channel volume.
(I would use one only at the start of a track).

Expression - Controller 11 used for swells and fades - true dynamics (particularly on held notes).
(I would use this for all dynamics, particularly wind instruments and strings).

Velocity - In MIDI implemented as part of the Note On message along with Note Pitch.
(I would use this for accents on wind and string instruments but can be used for dynamics in percussive and struck string instruments with no sustain capability).

In NWC a Note Off message is not used - instead the software uses a Note On message with a Velocity of zero (to turn the note off)- so a velocity of zero does mean silence.

If I enter notes in a sequencer (Cakewalk etc.) and set the Channel Volume and Expression high and Note On Velocity to zero I hear nothing.
But this doesn't seem to work in NWC.
I can edit the Velocity of each individual note in a sequencer but I see no way of doing this in NWC without entering a dynamic velocity over-ride on every note - which seems impractical and as you have discovered seems to have little effect.

Dynamics in NWC have always been a puzzle to me.
Perhaps a query to NoteWorthy support will provide an answer.

--------------------------------------
Barry Graham
Top Brass Events Band
Melbourne, Australia
http://www.topbrass.com.au

Re: What does a velocity override of zero mean on dynamics?

Reply #2 –
Checked again in NWC.

A dynamic with a Velocity over-ride of anything above zero does in fact reduce the dynamic output.
But you can still hear a Velocity of one.
A Velocity over-ride of zero has no effect - it seems to revert back to maximum channel Volume.

In MIDI generally Velocity zero = silence.
Not so in NWC apparently.
Yet this is the method used to turn a note off !

Puzzling !

Re: What does a velocity override of zero mean on dynamics?

Reply #3 –
Until NoteWorthy makes a declaration I will have to posit that zero = whatever the default is.  That is, in interpreting the value given by the user, zero is treated as a reset, not passed on into the MIDI stream.

Re: What does a velocity override of zero mean on dynamics?

Reply #4 –
In NWC, please refer to Help on Insert Dynamic Command, the second paragraph.

In the MIDI protocol, a 0 note velocity is actually a note OFF event.

Re: What does a velocity override of zero mean on dynamics?

Reply #5 –
Thank you for the explanation, which I did miss.  So, does this mean that there is no way to turn off the sound, dynamically, on only one staff of a group using the same channel?

Re: What does a velocity override of zero mean on dynamics?

Reply #6 –
This is essentially true. However, you can probably set Expression to 0 with an MPC, and achieve your desired result.

Re: What does a velocity override of zero mean on dynamics?

Reply #7 –
Thanks for the explanation Eric.
But wont the Expression Controller affect all staves sharing the same channel?
I think Cyril's requires a Tacet on repeat (or Play 2nd Time Only) for notes on a staff that has a channel in common with other staves.

Re: What does a velocity override of zero mean on dynamics?

Reply #8 –
Yes, which is why I stated that this is essentially true.

Re: What does a velocity override of zero mean on dynamics?

Reply #9 –
Thanks again.  I am assuming that in the last reply the "yes" refers to the expression affecting the channel, note the staff.  That is what I have done.  Velocity seems to work as well, while still grabbing requiring multiple channels.

Since (for reasons of sound versus sight) I already have different numbers of measures in the visible and audible groups of staves I suppose I could simply eliminate the repeats in the audible, while leaving them in the visible, group.  By using a large numerator in the audible I could keep the difference in number of measures fairly small, making it not any harder than at present to keep track of the correspondences between the groups.

From experience it seems that NWC doesn't really care about equivalence of measures, just as long at the time is synchronized.