and Old Roman repertories differ mostly in ornamentation and surface detail. Old Roman chants are much more stepwise and gently undulating than Gregorian chants. Skips, even of thirds, are much less common in Old Roman chants than Gregorian. Gregorian chants often have a pentatonic structure, reinforced by their skips, while Old Roman chants are simpler in structure but more ornate, with more individual notes. Old Roman chants have intricate melodic motion within a narrow ambitus, with small, repeating melodic motifs, which are common in the Italian chant traditions such as the Ambrosian and Beneventan. Old Roman chants are often highly melismatic, with melismas blending into one another and obscuring the underlying melodic structure. Repertoire Chants of the Mass The Ordinary of the Mass appears to have been borrowed directly from the Gregorian repertory. The Proper chants of the Mass show some special characteristics. Introits in the Old Roman Mass retained the versus ad repetendum, a repeat of the verse, which had disappeared from the Gregorian chant by the 11th century. Musically, Old Roman Introits resembled their Gregorian counterparts, although the neumatic passages were more ornate and the syllabic passages were simpler. Old Roman Graduals fall into the same centonization families as their Gregorian counterparts, although with variations. For example, there is a family of Old Roman Graduals related to the Iustus ut palma family of Gregorian Graduals, which is named after one of the Gregorian Graduals that belongs to this family, but the Old Roman version of Iustus ut palma does not itself belong to this family. Old Roman Alleluias have a melodia secunda or alleluia secundus, an elaborate repetition of the opening jubilus, similar to the Alleluia in Ambrosian chants. There are fewer distinct Alleluia melodies than in the Gregorian repertory, and unlike the Gregorian Alleluias, some Old Roman Alleluias have verses in Greek. Some Old Roman Offertories used a repeating neume called the torculus, such as a repeating pattern of the notes D-E-C. This formula is one of the most distinctive musical formulae in the repertory. Some Offertories also include extended melismas of a style not found in any other chant or chant tradition. Chants of the Office Less is known about the chants of the Office. There are only about half as many melodies among the Old Roman Responsories as in the Gregorian repertory. Originally, Old Roman Repertories repeated the respond in full after the verse. This