Back in the 1980s I was fascinated by sound synthesis and analysis. The most well-known work I did was a little application called SoundCap (for Sound Capture) that was coupled with an Analog-to-Digital converter initially sold by Fractal Software, my partnership with Tom Hedges, and eventually sold by MacNifty. It is fortunate for many of the early Macintosh developers that this box hooked up to the back of a Mac through the serial port. Several sound-producing apps were produced with it, including Airborne! by San Diego's Silicon Beach Software.
Stephen St. Croix was a friend of mine. He contacted me at Fractal Design in the 1990s and wow'ed me with a few of his wondrous stories. We spoke at length on several occasions about digital sound synthesis, one of my many hobbies. I was surprised to learn that he was one of the inventors, at Marshall Electronics, of the Time Modulator, the box that introduced digital delay line flanging to more than a few famous musicians.
The most interesting story he told me was about the job he did with Lay's. Yes, the people who make the potato chips. It seems that their spokesman, Jack Klugman (of Quincy fame), had lost his voice as a result of throat cancer. This really made a problem for them because his commercials for Lay's potato chips were pulling quite well. After all, he was a very recognizable and a well-loved actor. His voice was distinctive. People listened to him.
Stephen informed me that they invented a new kind of voice synthesis device to recreate his voice. It used formant synthesis. Incredibly, they could exactly duplicate the distinctive gravelly sound of his voice in this manner! It seems that the very low-frequency warbling of his vocal cords, though inimitable by human voice impersonators, was entirely imitable by digital synthesis techniques.
At Marshall Electronics, they spent quite some time analyzing sound. They had room analyzers. And so they also had room simulators. But the least known cleverness involved voice analyzers. Imagine picking apart someone's voice, layer by layer. Figuring out the pitch-profiles and the syllabic inflections. Hand-tuning the cadence of the words. My mind was boggled constantly by Stephen's work.
I informed him of my work in music extraction. I had a special application called Do-Re-Mi that allowed you to whistle a tune that could be output using MIDI in key duration format, complete with amplitude and pitch profiles suitable for modulating a pitch wheel and a volume pedal. It could tell you how many cents (hundredths of a semitone) sharp or flat you were when you whistled. I used a clever correlation technique that involved a time-delta histogram for correlation, pitch-multiple disambiguation, Lagrange peak-finding, and other techniques for isolating the pitch accurately. This work was all done in the 1980s, before Fractal Design, as part of Fractal Software's work.
Tom Hedges, of course, was the hardware designer of the first Macintosh sound sampling box and my contribution was the software, much of it written in Motorola 68000 assembler. Our work with sound continued when we did a bit of work with Bogas Productions, involving Ed Bogas, Ty Roberts, Neil Cormia and others. I met them through a mutual acquaintance, Steve Capps, who was working on the Finder in 1984.
I wrote a sequencing application in 1984 and Tom was fascinated by it. He modified it so it could sequence samples and then proceeded to digitize his piano, note for note. This was in a day when samplers existed, but were quite crude and expensive. He encoded Rhapsody in Blue (he was so proud of playing it) and also a perennial favorite, Wasted on the Way (a thickly vocal-harmonic piece from Crosby, Stills, and Nash). We were both musically literate, but in different ways. I was a composer who played piano and I was fully familiar with sheet music (actually, I had to teach the rudiments of it to Tom before he could digitize the songs, which took a week or so to get it just right). Tom was a DJ with KZSU Stanford and an advanced audiophile. And he had a very wide understanding of music. His father played piano (which explained Tom's interest in Gershwin's Rhapsody in Blue).
So when I began speaking with Stephen St. Croix, I was very deep into audio analysis and synthesis. And the author of a very popular application for sound manipulation on the coolest new computer around, the Macintosh.
It wasn't a big surprise at all that we spent hours and hours talking about sound synthesis, analysis, music, and the recording business. Crazy times and a really good guy.