I may be missing something really obvious here, in which case apologies. I'm looking to vary the velocity of a synth part via a slow LFO (eg having two parts in which one gets almost imperceptibly higher velocity over thirty or so bars, as the other does the opposite, and back again, in a sine wave). I appreciate I could draw these in the track, but wonder if there is a VST option or simple thing in Sonar that I've overlooked?
 
Thanks for any advice.
 
Best wishes,
 
Malcolm

You can draw automation with a sine or triangle wave but I don't think you can do it with velocity. I also wouldn't know how to do it over thirty bars. I would say if one arc is over thirty bars, you probably don't have to go up and down again very often so just draw it.

To do it with velocity, just select the notes in the 30 measures and do a Scale Velocity, specifying the start and end velocities in the dialog. Then do the next 30 measures in the opposite direction (if you went up, then do the next 30 going down) and so on. This will give you a triangle wave for velocity modulation, which is somewhat similar to a sinusoid.

If you just want a volume swell/fade, and not alter at the same time any other functions that the synth may have assigned to velocity, then Melda Production's MMultibandTremolo may do what you want. It's an audio effect, not MIDI so would go on the synth's audio track after the synth.
 
It can handle incredibly long modulation times and just about any wave form you can think of. What's more, it's free.
 
https://www.meldaproduction.com/MMultiBandTremolo?kw=mod
 
Velocity changes would give a different result, as (depending on the synth's amplitude envelope of course) notes would only change in volume as each note was played, while a tremolo will change the volume of notes throughout their length. But for a straightforward volume change over time it's a good effect.

Thanks very much for the advice. I'll try the melda vst for audio volume and scale velocity for midi.
 
Best wishes,
 
Malcolm