Sketch A composer's autograph notation of a work in progress. Sometimes a sketch can be identified as an early stage of a known composition, or sometimes it represents a projected but unfinished work. A sketch may be no more than a brief fragment, or it may be a draft of extensive segments of a piece. Sketches of unfinished compositions have occasionally been used as the basis for posthumous completion: Su"ssmayr's completion of the Mozart Requiem is an early example.
Instrumentation The particular combination of instruments employed in any piece.
Franz Xaver Su"ssmayr (1766-1803) A composer who studied with Mozart in Vienna. After Mozart's death Constanze (Mozart's wife) engaged him to complete the unfinished Requiem K. 626; scholars have argued ever since about the extent of Su"ssmayr's contributions.
Proper of the Mass Those items of the Mass and Office of the Roman rite whose texts and melodies vary with the occasion, as distinct from those whose texts remain the same throughout the liturgical year and thus make up the Ordinary.
Dies irae Latin, "Day of wrath." A rhymed sequence [a type of hymn sung before the Gospel at Mass]. The text of the Dies irae is attributed to Thomas of Celano (d. ca. 1250). One of four sequences retained by the Council of Trent during the Counter-Reformation, it was officially made part of the Requiem Mass in the 16th century, but had been incorporated into the Requiem in some localities from as early as the 14th century.
Major mode One of the modes of the diatonic scale, oriented around C as the tonic; characterized by the interval between the first and third notes containing four semitones.
Minor mode One of the modes of the diatonic scale, oriented around A as the tonic; characterized by the interval between the first and third notes containing three semitones.