Train your ear
Ear training: we play, you recognize
The mirror image of Play along: we play a chord or interval ourselves and you recognize it — no microphone needed, so no permission prompt either. Five exercises: hear whether it's major or minor, which chord played, which interval it was, whether you can follow a chord change, and whether a string sounds in tune or out of tune.
We play a chord. Does it sound cheerful (major) or dark (minor)?
The audio plays entirely in your browser — the same synthesis as the chord buttons elsewhere on the site, no samples, no server.