MusicReasonEar Training and Playable Exploration
Which chord pattern did you just hear?
Choose a key and reveal which named Roman-numeral pattern was realized. This tool builds real chords from a small Locked pattern vocabulary and plays them after your gesture. It never infers your general ear-training ability from one exercise, and it never analyzes or references any commercial recording.
Answer
Want to learn more? What Ear Training Exercises Can and Cannot Measure
Understand
A functional pattern such as ii-V-I or I-IV-V is defined purely by scale-degree numbers, not by any specific absolute pitch, so the identical pattern sounds recognizably similar in any key even though every actual chord involved is different. Training the ear to recognize the pattern rather than memorizing specific chords is exactly what transposing the same pattern across different keys is meant to build.
Worked examples
The I-IV-V pattern in C major realizes as C, F, and G; the identical pattern in G major realizes as G, C, and D, a completely different set of chords built the same structural way. Replaying a prompt never changes which pattern was generated, so repeated listening always compares against the same answer.
Method and limitations
The selected pattern's scale-degree sequence maps onto the stated key's own diatonic degree table, producing real chord roots and qualities exactly the way Roman Numeral Analyzer reads them in reverse. Each chord is voiced from the same locked voicing family used elsewhere on the site and scheduled for playback only after your gesture. This tool excludes the key, the selected pattern, your answer, and any score from analytics entirely, and it makes no claim about musicianship beyond this one bounded exercise.
The Locked pattern vocabulary is kept small and named on purpose: I-IV-V, ii-V-I, and I-V-vi-IV each have a genuinely distinct sound worth learning to recognize individually, rather than diluting the exercise with dozens of similar-sounding variants at once. Widening the vocabulary later would need its own review of which additional patterns are distinct enough by ear to be worth adding, not simply appending more numeral sequences.