Is it possible to pass numbers from a [bp~] to an array using Pd-vanilla? I'm assuming it should be, but all the examples I find are for Pd-Extended and they don't work with vanilla.

@MDobleZ [tabwrite~] will show the audio output in an array..... in extended and in vanilla....... if that is what you are looking for.
bp~-help-array.pd
If not then upload your example patch that is not working in vanilla and we will translate it for you.
David.

I have 6 [bp~]s and I want each of one to be represented by a different column in the array going from low to high with the frequency.

@MDobleZ So is it the level of output of each [bp~] that will be shown in the columns or the frequency set for each [bp~] that will be shown in the columns?
If you upload the patch that doesn't work (that you found in an example) that will make it easy to see what you are trying to do........ click the up arrow with a bar below it at the top of the window when you are writing a post and then upload the patch.
Otherwise please provide an internet link to the example you found for extended...... copy and paste the url from your browser window into your post.
David.

Solved! The problem was apparently you cannot connect [pd~] directly to a message; it has to go through an [env~] first. Thanks, @whale-av.