What you say is all true, but only for stuff that comes from big-name bands or artists with the potential to be one. I do think there is quite a large community of bedroom producers/artists out there that will never get near a record deal or anything more substantial than tiny sales on iTunes or views on YouTube - less good musos who can't easily make out the chords (like myself) and those in the less profitable musical genres (electronic/dance and metal) where there are many, many more amateurs or hopefuls than successful acts. Anyway, I think there's a definite market for this plugin among the bedroom set. AU users (who I forgot abuot because I'm not a mac owner...oops) are more likely to pay money than VSTers, but a friendly Lite version will definitely drive sales of an affordable Pro version.
The Pro Tools folk will have little to no use for this plugin - let's face it, if you're paying for PT, you probably don't need the computer to help you with working out the chords. I think you're being a little unfair to Windows audio though. I used to produce on a full-size Pro Tools HD rig, but at home I've always been a Win/PC guy and don't find it limiting. I think the lean to Mac is just because they were the leader in that space for such a long time.
I was really surprised you didn't mention Ableton Live in your otherwise excellent roundup, though of course that's much more for dance than other DAWs.
Forgot about Live. Supports VST and AU (mac version only).
At any rate, my argument was (although I didn't explicitly lay it out) that he should cover AU for the garageband kids (bulk of the users) and the actual musicians that use Logic at band practice (sizable minority), and maybe catch VSTs on the way out for the Windows folks if it's not too hard (I'm not a VST developer; I can't say). AU is where it's all going though--you've got a generation of people growing up with garageband for recording, producing, even taking piano lessons. I would imagine that would be prime market for a chord detection app. In addition, the GB/Logic family file format is based around chord notation (and is pretty easy to reverse engineer), so you could actually export the chord structure back into the arrangement if you were clever. This has all sorts of interesting implications for chord-aware events like Apple Loops-- mixing would be drag and drop even for the people who don't know one chord from another.
Agree that Pro Tools isn't much use for this sort of thing. I do know a couple of kids who've picked up Pro Tools LE because they think it's what the cool kids use, but it's not worth the effort to capture.
Another obvious direction for this would be an iPhone app that displays the chord it currently hears (and does so accurately). Not sure how good the algorithm is from a bad source, but that would be worth $50 to me.
The Pro Tools folk will have little to no use for this plugin - let's face it, if you're paying for PT, you probably don't need the computer to help you with working out the chords. I think you're being a little unfair to Windows audio though. I used to produce on a full-size Pro Tools HD rig, but at home I've always been a Win/PC guy and don't find it limiting. I think the lean to Mac is just because they were the leader in that space for such a long time.
I was really surprised you didn't mention Ableton Live in your otherwise excellent roundup, though of course that's much more for dance than other DAWs.