Patch Busses and Groups | SuperCollider 3.13.0 Help

s.boot;

a = Group.new;

b = Group.after(a);

c = Bus.audio(s,1);

p=Patch({ arg in,ffreq;
    // the Bus is passed in as In.ar(bus.index,bus.numChannels)
    LPF.ar(in,ffreq)
},[
    c,
    KrNumberEditor(3000,[200,8000,\exp])
]).play(group: b);

// play something onto this bus in a group before that of the filter
y = Patch({    Saw.ar(400) * 0.1  }).play(group: a, bus: c );

z = Patch({    Saw.ar(500) * 0.1  }).play(group: a, bus: c );

z.bus
z.synth
z.group
z.server

z.stop;

y.stop;

// z and y are now stopped by p is still playing

// c is a Bus object
c
// play c ontto a main audio output
c.play

//use command-. to stop all

s.boot;

a = Group.new;

b = Group.after(a);

// no index, not yet allocated
c = Bus(\audio,nil,2);

y = Patch({ arg in,ffreq;
    LPF.ar(in,ffreq)
},[
    c, // a proxy, the bus is yet to be allocated
    KrNumberEditor(3000,[200,8000,\exp])
]).play(group: b);

// now that the patch has played, the bus allocated itself
c.insp

// play onto this bus in a group before that of the filter
z = Patch({    Saw.ar([400,401]) * 0.1  }).play(group: a, bus: c )

helpfile source: HelpSource/Guides/Patch-Busses-and-Groups.schelp
link::crucial-library/Guides/Patch-Busses-and-Groups::

Patch Busses and GroupsExtension

Patch Busses and Groups
Extension