"how similar" and "the same or not" are two different things.

to compare 2 lists there is [zl] – in max 5 i *think* it takes "compare" as
argument.

what also works, and what i do since many years, it to convert a list to
a symbol – "60 64 67" – and then compare that using [zl union].

-110

look at the third party externals zsa.descriptors by emmanuel jourdan. the one you want is zsa.dist I would guess…

http://www.e–j.com/?page_id=83

(let my first correct myself: of course i dont convert lists to symbols in
order to compare, thats bullshit. i do it the other was round!)

"The next chord has a peak at 443 Hz and a little louder"

yes, i understand now. i think what you want is simply to quantize and
truncate your freuquency data.

first of all please convert all your frequencies from Hz to note numbers
(midi note numbers – but in floating point).

note numbers are linear, and that makes thing so much easier to understand
and to calculate!

442 and 443 Hz will than be something like note number 59.9 and 59.94,
and you can make up all kinds of tests against other notes.

you could truncate to integer, so that both values will be converted to 60.0
and if you compare they wil now be "the same".

or you could make up a custom rule saying that everything between a
difference of 0.001 – 0.1 is "very similar" and from "0.1 – 0.33" you call it "similar".

-110