> On 07/19/2011 02:45 AM, pshir...@boosthardware.com wrote: >>> On 07/18/2011 04:02 AM, pshir...@boosthardware.com wrote: >>>>> On 07/17/2011 10:41 AM, Rustom Mody wrote: >>>>>> On Sun, Jul 17, 2011 at 1:21 PM, Philipp Überbacher >>>>>> <hollun...@lavabit.com>wrote: >>>>>> >>>>>>> Excerpts from Rustom Mody's message of 2011-07-17 05:33:44 +0200: >>>>>>>> I am preparing to give a talk on the wider ramifications of music. >>>>>>>> One of the things I wish to demonstrate is that things that look >>>>>>> different >>>>>>>> are merely analogs but at different scales. >>>>>>>> >>>>>>>> eg if something vibrates at 400Hz we hear a sound of A-flat. If it >>>>>>>> 'vibrates' at 4 Hz we hear a beat. >>>>>>>> In the same analogy a 2 vs 3 poly-rhythm (should?) change to a >>>>>>>> do-so >>>>>>> chord. >>>>>>>> And so on. >>>>>>> >>>>>>> I suggest you do some experiments before you give a talk. At 4 Hz >>>>>>> you >>>>>>> won't be able to hear anything, you won't even be able to reproduce >>>>>>> a >>>>>>> 4 Hz sound with common speakers. >>>>>>> >>>>>> >>>>>> You took me quite literally, [I did put the vibrate into quotes :-) >>>>>> ] >>>>>> Let me spell out the experiment in more detail: >>>>>> Say I have a rhythm in 4/4 time -- 4 even quarter notes, bar >>>>>> repeating >>>>>> every >>>>>> second played by say a click. [What kind of click I am not very >>>>>> sure; >>>>>> sharp >>>>>> with few harmonics would be best I expect] >>>>> >>>>> Exactly. Just take a short audio-sample (aka grain) and trigger it >>>>> repeatedly. Increase the trigger freq. (aka grain-speed) from 4 Hz -> >>>>> 400Hz. >>>>> >>>>> Search the net for granular-synthesis. Your use-case is not the >>>>> typical >>>>> grain-synth application, but the principle is the same. >>>>> >>>>>> Now if there were some (realtime) way of sliding the tempo from 1 >>>>>> sec >>>>>> to >>>>>> millisec I expect the separate clicks would vanish into a hum at >>>>>> some >>>>>> stage. >>>>>> >>>>>> This (and other such experiments) is what I want to demo. >>>>>> Ive started looking at chuck. >>>>>> How does it compare with puredata? >>>>>> >>>>> >>>>> It's a bit of an apples vs oranges question. >>>>> >>>>> the main difference: Chuck you program in text, pure-data you >>>>> graphically connect "objects" (if you know Max/MSP: pure-data is >>>>> similar). >>>>> >>>>> AFAIK, Chuck does not offer GUI elements - you'll need to implement >>>>> the >>>>> slider via OSC or use a "text slider". >>>>> >>>>>>>> Is there some kind of software where I can make a 4 Hz beat and >>>>>>>> pull >>>>>>>> a >>>>>>>> slider or a freq text box entry until it sound like a A-flat note? >>>>>>> >>>>>>> puredata springs to mind, it's easy to use and has everything you >>>>>>> need. >>>>> >>>>> Indeed. Though chuck, supercollider, csound,... could all do the >>>>> trick. >>>>> >>>>> If you know neither of those. Pure-data is probably the easiest to >>>>> get >>>>> started with. >>>>> >>>>> http://www.timvets.net/video/grains.php will do what you want with >>>>> Pd. >>>>> >>>> >>>> >>>> I'm not sure that does what he wants. He asked for a tool that takes >>>> an >>>> existing signal/tone and then down tunes it. What you are suggesting >>>> creates an emulation of that process but generates a completely new >>>> signal/tone. >>>> >>>> It would achieve a similar sound but is functionally quite a different >>>> process. >>> >>> You are right or course. It's not modeling the desired effect >>> correctly; >>> Yet it's close enough and much more robust and convicing for a Demo. >>> >>> Actually http://www.sonicvisualiser.org/ may be the tool of choice. >>> Here's a video where it is used to slow down some Bach so that you can >>> hear the "beating/pulsing" introduce by equal-temperament tuning: >>> http://www.youtube.com/user/mcldx#p/a/u/0/uOOhvw89jc4 >>> >> >> >> That's an interesting feature of that tool. I was not aware of that >> functionality. It appears to work on the time domain not the >> amplitude/phase of the signal. I assume as it uses a similar code base >> to >> librubber band to achieve that functionality. >> >> IIRC, It is still not quite doing what the original request appeared to >> be asking for. i.e. down tuning an existing signal. ( He didn't require >> time adjustment ) >> >> Would it just be a case for a pitch shifter with a automation fade curve >> sone in Ardour/qtractor, etc...? >> > > The SuperCollider one-liner that Bernardo posted is actually brilliant. >
Sure, IIUC it doesn't take an existing waveform and down tune it. But I don't know enough about SC to know what that code snippet really does. It looks like it generates a tone then down tunes it. -- Patrick Shirkey Boost Hardware Ltd _______________________________________________ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev