A couple years ago I took an in-depth look at Capo, the music-learning app designed to reverse engineer music on your Mac, making music easier to hear, and therefore easier to learn to play. Capo has seen a major update since then to 3.0, bringing some big new features and enhancing the best of the previous version. Better still, it's cheaper, too, at US$29.99 on the Mac App Store.
Since I covered most of what Capo has to offer in my previous review (which you can read here), I'm going to jump straight into Capo's new and enhanced features.
Capo has enhanced its spectrogram feature (analyzing the audio in a track) to automatically detect chords that are played in a song. Furthermore, the chords are placed in chord boxes that show you how to play the them, with easy-to-read chord descriptions, and where the changes are in the song. You can also try different variations of chords from the box, just double-click a chord box to see a variety of different inversions.
Chord detection isn't flawless. I noticed that more subtle chords were often not detected, and chords were sometimes not placed coherently in the song. For example, at the start of a bar. This is all down to the spectrogram's analysis of the music. The detection accuracy will vary from song to song as some songs will be easier for the software to analyze than others.