Conference napalm::commusic_v1

    There is a commercial studio product call the Eventide Harmonizer that
    does time distortion without changing the pitch.  I recall a famous
    conductor going public, disclaiming responsibility for his latest
    record release, because the record company had compressed the symphony
    in time to make it fit in the LP format.
    
    So perhaps contacting Eventide might be an option.  Of course they may
    also consider their interpolation/compression algorhythms to be
    proprietary.
    
    karl

	There are many pitch shifters.  If you can change the speed of
	playback, the pitch shifter will correct the pitch.  However, the
	output is a little fluttery, more so with larger changings of pitch.
	The Yamaha SPX90 does this, so maybe might the Roland DEP 5.
	At much lower prices than the Eventide.  Eventide may or may not
	be considered top of the heap; someone else whose name escapes me
	is.  These expensive units might be higher quality. I'm not sure.
	The conductor probably got a pitch shift by playing the tape faster,
	so the performance was very distorted.  I doubt they used pitch
	shifting, but it's possible I suppose with incredibly high end
	units.
	Radio Shack used to sell a tape recorder with pitch shift
	that I rigged up to accept external line signals; it could only shift
	down (it was for listening to lectures played back fast), and
	was Charge-coupled device-based, and was real hummy and noisey.
	Probaly the best way to synch up music, for which people have a lower
	tolerance of low fidelity (what with the proliferation of
	CDs) is to edit it, either on tape or digitally.
	Tom

    And, of course, there's the digital workstation thingy that Lexicon
    systems won an Academy Award (not Grammy) for, which compresses and
    expands time. The device is used to make music segments fit scenes in
    movies more exactly. 
    
    All that domain transform mumbo jumbo you learned in college really
    works.
    
    dp

Hi there !

There's also the AKAI U5 (or is it U4) Phrase Trainer that does both time
compression and pitch correction. And it's a lot cheaper than the other units,
even though the capacity is only for phrases of a few seconds.

	Richard

  The DECtalk products from Digital do exactly that, change the speed of
  speech without distorting it.  Now I'm not sure if that was as simple as
  changing the pause duration between spoken words or what.  And of course
  this is voice synthesis, as opposed to real-time modification of incoming
  analog/digital audio.

  But in any case, I would guess the engineers in the DECvoice group would
  be a good place to check.  They must have slews of these sorts of algorithms,
  some of which are probably proprietary, but available for other in-DEC use.

-TR

    If you're interested in doing this with sample waveforms, Alchemy (from
    Passport, formerly from Blank Software) does the job quite well.  As a
    software product, it's quite expensive, but it does things like this
    that other sample editors don't do.  
    
    It does not do this in real time -- it actually recomputes the new
    waveform over a fairly appreciable time interval and then you upload
    the sample back to the synth.  You can, of course, also listen to it
    over the Mac internal audio output.  The computation it does, though,
    is right on the money and has very little in the way of annoying
    distortions or artifacts.
    					-- Mike
    

     Sorry I'm late in getting my entry in...  

     I have thought about how to do this for some time, to have correct 
     pitch, but slowed down time.  I've wanted to do this for a band 
     project, and I try to use equipment on hand. My solution (untested) is
     to record the vocals on tape, play through a harmonizer set to, say,
     a fifth above, and sample the output.  Select the root key and play the
     note a fifth below.  The sample should be at the correct pitch, and 
     should be about 1/3 again as long in time as the original.Fine tuning 
     on the pitch control would give more precise control on playback time.  

    That is what them 'digital slo-mo" things that are advertised in guitar
    world do isnt it?