Monday, June 8, 2015

How to Graph the Pitches of Instruments

Graphing the pitches of instruments can be completed using either the sounding pitch or frequency of the instrument. For most people, the easiest method to graph pitch involves using scientific pitch notation. In this type of notation, the sounding pitch includes a number that designates the octave it sounds in. For instance, middle C would be written as "C4." The octave below middle C is "C3," and the octave above is "C5."

Find the instruments total range. You can use an orchestration text to find this information. For instance, a typical piano has a range from A0 to C8, or 28 hertz to 4,186 hertz.

Create an X and Y axis on a sheet of graph paper; the X-axis extends horizontally, the Y-axis extends vertically.

Write in numbers below the X-axis starting with one. The numbers will represent time in the music, and each number will equal one beat.

Write each pitch on the Y-axis, including the scientific pitch notation. If there are several numbers, you may wish to condense the graph and include only the octaves. The actual pitches can be approximated by viewing their relationship by distance between one octave point on the graph and the next. You can also reduce the graph to use only the pitches that you need to graph. For instance, if the instrument has a range of four octaves, but only uses one octave in a musical work, just graph the pitches for the utilized octave.

Plot the pitches on the graph by placing a dot for each pitch used in the music on the graph. Line up the beat on which the pitch appears and the actual pitch used, and place it on the graph at the point where the two points converge. Think of the X-axis as having lines that extend vertically from each beat, while the Y-axis has lines that extend horizontally across the plane. Place your dot at the point where the two lines merge. Tips If you wish to simply graph several instruments in relation to each other, follow the instructions but use instrument names instead of beats on the X-axis. Draw a bar from the lowest to the highest pitch for each instrument.

References


UreMusic: Treble and Bass Clef Notation http://uremusic.com

Peabody: Pitch to Frequency Mappings [http://peabody.sapp.org/class/st2/lab/notehz/]

"The Study of Orchestration"; Samuel Adler; 2002