Many thanks for the reply! Actually there is another, very odd reason why my example did not work. Even if I used your working example, I found out the following odd behavior: If I have a statement that does: Out.ar(out, SinOsc.ar(freq, mul: 0.5)) Then it works. If I have a statement that does: Out.ar(out, SinOsc.ar(freq * 100, mul: 0.5)) This also works. Now if I have: Out.ar(out, SinOsc.ar(freq + 100, mul: 0.5)) This doesn't. Naturally, one could always put something before this statement to fix this, i.e.: freq = freq + 100; Out.ar(out, SinOsc.ar(freq, mul: 0.5)) But it is still interesting why the multiplication works and addition doesn't. Also, I noticed that on one of your SCUM example screenshots you are using .connect method to connect something, yet I was unable to locate anything of value in the documentation. I assume that this could be something similar to the signal-slot idea in Qt and/or other Widget languages (but obviously I may be completely off the mark), so I was wondering if you could please provide an example for that? I would really appreciate it! Finally, while I am on the roll with questions :-), do you mind also mentioning what's the current status/roadmap of SCUM in terms of supporting all stock Supercollider widgets, as I noticed that the SCUM widgets use non-standard names and in addition I am not sure whether all widgets are as of yet supported, all of which, at least in my experience, makes a number of sc examples available on the net difficult if not impossible to run in Linux. Please don't get me wrong, this is not to criticize as I am eternally grateful for SCUM, I am simply curious as to what is the roadmap for the project. Many thanks to all for your help! Best wishes, Ivica Ico Bukvic, composer & multimedia sculptor http://meowing.ccm.uc.edu/~ico/ > you'll have to split up the code: > > s = Server.local.boot; > > SynthDef(\testfest, { arg out=0, freq=440; > Out.ar(out, SinOsc.ar(freq, mul: 0.5)) > }).send(s); > > z = Synth(\testfest); > > ( > w = SCUMWindow.new; > w.title = "Slider example"; > w.initialSize = Size(20, 300); > > c = SCUMVBox(w); > v = SCUMSlider(c, { |v| > v.expand = 1; > v.fill = 1; > v.bgColor = Color.white; > v.fgColor = Color.black; > v.action = { z.set(\freq, v.value * 100 + 400) } > v.doAction; > }); > > w.show; > ) > > hth, > <sk>