source file: mills2.txt Date: Sun, 16 Feb 1997 20:52:42 -0800 Subject: Re: can anyone explain these "ghosttones"? From: Gary Morrison > Plucked strings are not harmonic, and noticeably so in many cases such > as pianos. Percussion instruments (you mention bells) have components > that depart even further from harmonic ratios. Uhmmm... Well, that may perhaps be true of SOME plucked strings, maybe perhaps violin or viola pizzicato. But I don't think the same can be said for many, and possibly the majority, of plucked strings, including 'cello and bass viol pizzicato and guitar. I say that because I personally have decomposed and then additively resynthesized those tones with partials forced to be strictly harmonic. What ever would posess me to do that? Because for a long time that's all my program would do (analyze down to the nearest strict harmonic). I had a regular test suite of about two hundred woodwind, brass, orchestral and plucked-string, bell, piano, pipe organ, wood-bar, and metal-bar instruments, and timpani. I ran those sounds through the program frequently as I developed it. It's very easy to hear that, in being forced to strict harmonics, the strings (excluding the high register of the piano), woodwinds, and brass suffered only slightly, whereas the characters of the those percussion instruments, were vastly altered. The enormity of the difference for the strings (including the plucked strings), woodwinds and brasses I would characterize as slightly greater than the sort of thing that distinguishes a bad guitar (for example) from a good guitar. Another way to characterize the difference is that the unaltered and pure-harmonic tones were nearly indistinguishable from each other on the Mac's built-in speaker, although the strictly harmonic timbres had a crusty, buzzy, robotic quality when played back over big speakers in 44.1KHz 16-bit stereo. Received: from ns.ezh.nl [137.174.112.59] by vbv40.ezh.nl with SMTP-OpenVMS via TCP/IP; Mon, 17 Feb 1997 08:17 +0100 Received: by ns.ezh.nl; (5.65v3.2/1.3/10May95) id AA08286; Mon, 17 Feb 1997 08:17:35 +0100 Received: from ella.mills.edu by ns (smtpxd); id XA08280 Received: from by ella.mills.edu via SMTP (940816.SGI.8.6.9/930416.SGI) id XAA01368; Sun, 16 Feb 1997 23:15:22 -0800 Date: Sun, 16 Feb 1997 23:15:22 -0800 Message-Id: <33080319.630F@ix.netcom.com> Errors-To: madole@mills.edu Reply-To: tuning@ella.mills.edu Originator: tuning@eartha.mills.edu Sender: tuning@ella.mills.edu