Featured page
G Minor 9thThe G Minor 9th chord is a five-note chord made up of G, B♭, D, F, and A.
Piano chords, scales, theory & ear training
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Full identifier ›Today at the piano
Saturday, July 25, 2026. The Library resets daily: a featured page, a term, and a note of piano history, drawn from the same reference every deep page uses.
On this day
1883 Alfredo Casella, an Italian composer, pianist and conductor, was born in Turin.
Term of the day
G♭ Major Pentatonic ScaleThe G♭ Major Pentatonic scale contains five notes: G♭, A♭, B♭, D♭, and E♭.
Did you know
The lowest key on the piano (A0) sounds at 27.5 Hz; the highest (C8) at about 4,186 Hz.
Piano by the numbers ›Jump to any reference page
Chords, scales, and modes — every key, both enharmonic spellings.
The index
Look anything up directly, in both enharmonic spellings, C♯ and D♭ alike.
Learn and practice
The reference is for looking things up; these are for getting better.
Learn Piano: the step-by-step pathAn ordered course from your first notes through chords, scales and theory — no login required. Start here.Follow the pathChord FinderPlay or click any combination of notes and see what chord it makes.Open the toolChord and Scale MasteryGuided series that read like short books, from what is a chord to altered harmony.Start readingPractice RoomConnect a MIDI keyboard and get graded feedback on timing, evenness and accuracy.Enter the roomCircle of FifthsThe interactive wheel: keys, relatives, and how they connect.Explore it
Who writes this
Maintained on nights and weekends by Justin Evans, a pianist of 25 years. Report a mistake