the maths behind BPM…?

BPM = Beats per minute
there are 60 seconds in a minute
the amount of bass kick pulses (or beats) there are within 60 seconds will be the resulting BPM.

Depending on the music you’re using, creating a BPM detector (especially in Max/MSP) is a pain in the butt. i mean if cd’s with the fancy bpm counters go nuts with something that’s not "clearly" 4/4 it’s hardly going to be a picnic in the park…

i haven’t used max/msp in a good long time (it scared me off for a while) but i’d imagine you’re going to have to define probably a frequency range for it to listen to for the said ‘pulse’ and calculate the distance between each pulse within 60 seconds. the distance=Speed/time equation comes to mind although you’d have to change that to be relevant to BPM as opposed to physical distance etc.

say we reduced the sample time to 10 seconds and for arguments sake there were 15 pulses in those 10 seconds. multiply that by 6 and you’ll get 90bpm.

that’s probably not helped at all…guess i shouldn’t think/type simultaneously.

i’m doing (or should be doing but haven’t got time at the moment) which will require getting back into grips with max/msp and getting a beat/bpm detector working to trigger something else. i’m sure there’s an equation or a way to do it…maybe i’m looking in totally the wrong direction

I thought that first too, but like a said before it depends on what you’re sampling. it would be great to use volume threshold on a Benny Benassi or even an eric prydz track as they’ve compressed so much out of it, the 4/4 is exceptionally prominent.

maybe most BPM counters do rely on that…i’ve always wondered (never bothered looking) about that.

i’ve just thought it would be easier and yeald more convincing results if you set an object to listen to a set frequency range where the bass kick usually is (as opposed to snare/white noise)

Tell us how you get on with it…you’ll probably help me with my project too …when i get time for it again

i think you’re both missing the point…

the program the question is based in is MAX/MSP…all the stuff that you take for granted in sound editor software, you can make from scratch (or download patches from the forum). which is why the question was asked (i think?, correct me if i’m wrong).
the javascript page is interesting and one of them is going in the right direction of what i was thinking…but doesn’t quite get there (plus i don’t have max/msp installed at the mo)
probably still not making sense: http://www.cycling74.com/products/maxmsp

…seems logical that would be time= speed/distance (even though that’s not directly related to this, it kinda works in a similar manner)

or beats per minute=time(1min=6000ms)/distance between transients(95ms)

that looks like it would make sense/could work. even though it seems too simple, it’s usually the most simplest things that work the best (not much to go wrong etc.) why not try that and see if it works?

**edit** i take that back. just found a thesis by doing some googling. haven’t read it all but looks like there’s possibly some relevant stuff from page 43 in this pdf: http://eamusic.dartmouth.edu/~iroro/the … ddim.pdf**

if that link is a no no, i’m sorry mods