Muzio Clementi

Clementi was a working pianist, teacher, publisher and piano manufacturer, and he wrote the sonatinas that half the piano-playing world learns in its third year.

The Six Sonatinas, Op. 36 are the reason he is in every catalogue. They are perfectly judged teaching material — real music, properly written, at a difficulty a student can actually reach — and they are available free. The full sonatas are a substantial body of work that Beethoven admired and almost nobody plays. Gradus ad Parnassum is the advanced study collection.

The Op. 36 sonatinas are published by everyone, and the differences are entirely in fingering and editorial marking. For a student, the edition their teacher uses is the right one; for anyone else, any urtext will do.