The history of the A Form begins in the classical piano literature of the Nineteenth Century. This form first appeared in the piano works of Frederick Chopin and became one of the vernacular sounds of the Nineteenth-Century piano concerto. In this form, the third appears in the bass of the minor voicing, the seventh appears in the bass of the dominant voicing, and the third again appears in the bass of the major voicing. This is the older of the two forms and is usually more familiar to the average pianist for that reason.