Thanks simonk, I did not realize that 'pitch tune' output an analysis file. So of course that file has to be resynthesized. My command lines should have been:
pvoc anal 1 horn.wav horn.ana -c1024 -o4
pitch tune 2 horn.ana horntun.ana mididata.tun -f1 -c1 -t1 -b50
pvoc synth horntun.ana horntun.wav
It now works.
pvoc anal 1 horn.wav horn.ana -c1024 -o4
pitch tune 2 horn.ana horntun.ana mididata.tun -f1 -c1 -t1 -b50
pvoc synth horntun.ana horntun.wav
It now works.