So there's no way to change velocity values of multiple (not all) notes in a lane at once? I haven't fully read the step sequencer section in the manual, but it looks like it's not even possible to select multiple notes.  

There are several options. If you're in step-sequencer-land, there are velocity lanes for each row, where you can draw, use the line tool, etc. as you would with the velocity pane in the standard Track View. There's also a MIDI "master volume" control for each row, like the fader in a standard MIDI channel, so you can scale the row's velocities.
 
Those methods are, of course, oriented toward step sequencing because you're in the step sequencer view. However, you can convert to a MIDI clip if you want to use all the standard MIDI editing tools, as well as convert back to step sequencer view if you want to go back to using tools optimized for that view.
 
Furthermore, any MIDI plug-ins will affect the step sequencer. This is why I was confused by the use of the term "plug-in." Although you can't change all notes to a single value within the step sequencer itself, you can use the Velocity MIDI plug-in to play back all notes at a constant velocity, regardless of what the levels are in the step sequencer itself (as well as the other Velocity plug-in options, of course).

Jlien X
So there's no way to change velocity values of multiple (not all) notes in a lane at once? I haven't fully read the step sequencer section in the manual, but it looks like it's not even possible to select multiple notes.  

You can do this if you transfer the notes to the PRV.  Multiple notes can be adjusted at once by highlighting them and using the smart tool to drag the velocity values up or down.  It's very quick.  Also, once the notes are out of the step sequencer, there's a MIDI f/x tool that will do the job.

Thanks both. I'm not sure if Step Sequencer is worth using when the PRV is so great (I use it all the time), but I guess I just don't know the best part of SS yet. Maybe it's easier than drum maps. I'll spend some time experimenting with the feature.

For me it's a compositional thing...much better than a metronome.

I just wrote a CAL script for myself, to change all midi velocities in a selected track to an input value supplied by the user when they run the script.
 
I did this for myself, because I found that the default 100 was not giving enough vibrato in a solo violin patch I was using, so I wrote the script to change all the velocities to all be 108.
 
If something like that would work for you, just shoot me a Private Message with your email address, and I will send it to you.
 
And, I would also vouch for Anderton - he is 100% helpful 100% of the time.  (the results don't always work 100%, but the effort is real and I have never seen him be condescending or anything like that).
 
Bob Bone
 

robert_e_bone
I did this for myself, because I found that the default 100 was not giving enough vibrato in a solo violin patch I was using, so I wrote the script to change all the velocities to all be 108.
 
 

 
You use step sequencer for violins too?
Bob, when will you start learning how to use PRV? 
 

DOH! You caught me!
 
OK - I PROMISE that beginning Sunday, May 11, 2014, I WILL make DEDICATED EFFORT into learning to use PRV.  I WILL follow through with that promise - I have been putting it off for WAY too long.  No more dodging.
 
Bob Bone
 

 I was always put off by Midi. That was stuff keyboard players did. (I'm talking back in the day)
 
Then I got CWPA 6 and I found out I could write my own piano parts, organ parts, and drum parts! All in this new fangle thing called a PRV!!
 
I totally embraced it. I love the PRV. And when Drum maps came along, wow!! The new smart tools was really a challenge for me, but I have learned to use them and things are much better now.
 
The Step Sequencer however was something that I just didn't get. I tried to use it many times, but the results was always less than what I was after. But everyone would always talk about what they did with it, so I took another look at it. With some real effort, I found that it's much more powerful than I had originally thought. Some of the patterns I got with it were much better than what I was finding in my midi groove collection.
 
These are both very good tools that I really hope the bakers will update real soon.