Hi, Is the ChucK thread disrupted by the execution time of a Std.system script call? In the code below, sporking a fast script, e.g. Std.system("sleep 0"), there is no noticeable disruption, but sporking a time consuming version e.g. Std.system("sleep 3") there is a disruption in the other sporks. I'm trying to call R scripts using ChucK concurrency. // test code, run with --caution-to-the-wind command-line flag Noise n => Envelope e => dac; fun void metro() { while(true) { e.keyOn(); 10::ms => now; e.keyOff(); 990::ms => now; <<< now, "samples" >>>; } } fun void callSystem() { while(true) { Std.system("sleep 0"); // comment this to test //Std.system("sleep 3"); // uncomment this to test 1000::ms => now; } } spork~ metro(); spork~ callSystem(); while(true){10::ms => now;} // end test code