Musical notation and tables, 19th century. At upper left are a set of musical scores, showing examples of musical notation and keys. The diagonal diagram shows an entire or grand scale of musical notes, passing from the lowest key (bass clef) through the tenor clef to the highest key (treble clef). Below this are twelve chords, groups of notes that create a harmonious sound. The table at right shows the ancient symbols and names used for the Ancient Greek 18-note tetrachord scale, with corresponding do-re-mi-fa-sol-la-ti scale tones in the left column. This page is from 'Universal Technological Dictionary' (1823) by British author George Crabb (1778-1851).