Ask HN: What's a good way to estimate notes from music files

I'm trying to estimate what note is being played in an instrumental track. I'd tried to approach this problem with by splitting the track into its different instruments with open_unmix [0], and then using librosa pitch tracking [1], and then cleaned the results, but unfortunately, the midi came out totally unrecognizable. I thought about approaching this problem again when I saw the recent post on audio source separation [2], but that still only solves the problem of separating the vocals from the instrumental track and into separate instruments.

Is there a better/more state of the art method to pitch estimation than librosa's piptrack, or am I just using piptrack improperly?

[0] https://github.com/sigsep/open-unmix-pytorch

[1] http://man.hubwiz.com/docset/LibROSA.docset/Contents/Resources/Documents/generated/librosa.core.piptrack.html

[2] https://news.ycombinator.com/item?id=24748793