Hi!

What is the syntax for making a multichannel expansion of all the keys used in a Pbind?

This is possible:

```
Pbind(
\degree, Ptuple([Pbrown(-7, 0,1), Pseq([1, 2, 3, 4, 5, 6], inf), Pwhite(7, 12)], inf),
\dur, 0.25
).trace.play;
```

and this is also possible:

```
Pbind(
[\midinote, \dur], Ptuple([Pseq([1,2,3,4,5]+55, inf), Pseq([1,2,3,4,5,6].reciprocal, inf)], 1),
).trace.play
```

But why exactly this is not possible?

```
Pbind(
[\degree, \dur], Ptuple([
Ptuple([Pbrown(-7, 0,1), Pseq([1, 2, 3, 4, 5, 6], inf), Pwhite(7, 12)], inf),
Ptuple([1, 0.25, 0.5],inf)
], inf)
).trace.play;
```

It only provides a single note and then crashes throwing the error: `ERROR: Primitive '_Event_Delta' failed.`

. Looking at the trace, it seems to be providing a meaningfull multichannel expansion: `( 'degree': [ -7, 1, 11 ], 'dur': [ 1, 0.25, 0.5 ] )`

.

What is the explanation for this behavior?

Is there a guide/tutorial that deals exactly with multichannel expansion on Patterns?