Begin with a short, stable passage
Choose two or three chord changes with a clear accompaniment and listen for the movement of the harmonic foundation. Hum a possible root for each chord and find the notes on your instrument. Keep the exercise short enough that you can remember the contour. The lowest audible note can help, but it is not always the root because inversions and passing bass notes exist. Treat a bass pitch as evidence to test rather than automatically converting every low note into a chord name.
Bass line C–B–A, roots C–G–A
On a keyboard, play C–E–G over a low C, then G–B–D over a low B, then A–C–E over a low A. Hold each for four beats. The bass descends C–B–A, but the chord roots are C–G–A. The middle harmony is G/B: G major with B in the bass. Naming it B major from its lowest note would introduce D sharp and F sharp, neither of which belongs to the chord you played.
Try two reductions of this example. First play only the descending bass, keeping its smooth contour. Then play the roots C–G–A in a comfortable register. These reductions answer different questions. The first explains the bass part; the second tracks the chord identities. Sing G during the middle chord and then B, listening for how both belong to the same harmony. A stable bass note can be a chord member without being the root, so simply holding a candidate through a bar does not prove root status.
Compare the roots in context
Play the candidate roots with the recording using a simple, quiet sound. Listen to whether each note feels stable across the chord's duration. If one fits only briefly, it may be part of a moving bass line rather than the underlying root. Add a fifth above the root if that helps you hear the foundation, then test the major or minor third separately. This staged approach reduces the number of decisions you make at once and makes it easier to explain why one proposed harmony fits better than another.
Connect motion to reusable relationships
Once the roots are secure, describe whether they repeat, move by step, or leap by a larger interval. Try playing the same relationship from another starting note without worrying about a complete arrangement. Compare your original sequence with the AudioChords suggestions and investigate disagreements one at a time. Do not assume that a familiar root pattern guarantees a familiar chord quality on every degree. The benefit of root-motion practice is a stronger map of harmonic direction. It gives later decisions about inversions, extensions, and instrument voicings a stable reference instead of making every chord feel like an unrelated object.
Keep bass and roots on separate lines
For a more detailed test, give the first bar a bass line C–D–E–G in quarter notes while sustaining C–E–G above it. D is a passing event in this constructed example, not an instruction to replace C with a D chord. When studying an actual recording, write a provisional bass line and a separate chord line. Mark uncertain bass notes with a question mark instead of building elaborate chord symbols around them. If every upper part is obscured, root identity may remain less certain than bass contour. You can practice that contour now and revisit the harmony in a clearer repeated section.