Your target market is musicians. As said above, the iTunes model will work - indeed, so might an iPhone app.
But also, consider making it a VST plugin (VST = virtual studio technology, free SDK from Steinberg) It's the industry standard for non-pro users and works with all music recording/editing platforms on both Mac and PC. These kinds of users have no problem downloading & installing, and are more likely to pay - your pricing is quite reasonable, and moving what you do to VST shouldn't involve much overhead, the DSP will be the same. Make an option to output the chords to MIDI, which should be trivially easy. Better yet, make lite and pro versions - lite version maybe only does major chords or doesn't output MIDI.
3 websites (kvr, sonicstate and createdigitalaudio) will reach 90% of the plugin community. I'm at work so I can't test it out (and gave up using WinAmp long ago anyway) but I wonder how it copes with techno or orchestral music? I like making electronic stuff, but I just don't have a very good ear for chords and would love to have this as an analysis tool. Feel free to email.
But also, consider making it a VST plugin (VST = virtual studio technology, free SDK from Steinberg) It's the industry standard for non-pro users and works with all music recording/editing platforms on both Mac and PC. These kinds of users have no problem downloading & installing, and are more likely to pay - your pricing is quite reasonable, and moving what you do to VST shouldn't involve much overhead, the DSP will be the same. Make an option to output the chords to MIDI, which should be trivially easy. Better yet, make lite and pro versions - lite version maybe only does major chords or doesn't output MIDI.
3 websites (kvr, sonicstate and createdigitalaudio) will reach 90% of the plugin community. I'm at work so I can't test it out (and gave up using WinAmp long ago anyway) but I wonder how it copes with techno or orchestral music? I like making electronic stuff, but I just don't have a very good ear for chords and would love to have this as an analysis tool. Feel free to email.