Let us bless the Lord

The Abbey of St. Martial ac Limoges, in southern France, was the location of an important school that figures prominently in the development of organum during the years from about 1100 to 1150, preceding the more famous school of Notre Dame in the north. In the St. Martial style, the lower voice, or tenor, utilizes a phrase of Gregorian chant, each note of which is greatly prolonged, while the upper (organal) voice puts elaborate melismas in free rhythm against each tenor note. At the point where each tenor note begins, the two voices form intervals of a unison, fourth, fifth, or octave; between these points the tenor note behaves in the manner of a pedal point against the upper voice, which moves freely over consonant and dissonant notes at will.