Purpose:
To identify the locations of harmonics on an acoustic guitar and relate them to guitar string lengths.
Hypothesis:
If I pluck the sixth string of the guitar from frets nine- twelve, then those frets will not produce harmonics that are able to be heard clearly.
Materials:
Acoustic guitar ( adult or child sized)
Cloth tape measure, metric
Lab Notebook
Procedures on finding harmonics on your guitar:
1.Select a string and starting at the twelfth fret, try to play a harmonic in that fret by lightly damping the string above the twelfth fret.
a.If a harmonic is heard (and you hear a ringing, bell-like tone), then mark that location in your data table with a filled-in black circle.
b.If a harmonic is not heard (if the string sounds dead or dull or makes no sound at all when plucked), then mark that location in your data table with an open circle.
2.Continuing on with the same string, repeat step 1 for all frets, from fret 11 down to fret 1.
3.Repeat steps 1–2 for two additional strings.
Procedures on relating the location of the harmonics to the location of the strings:
1.Measure the length of one string, from the nut to the bridge, with the tape measure. (All strings are the same length on a guitar, so it does not matter which one you choose.) You will probably need a helper to take this measurement accurately. Write down your measurement in your lab notebook.
2.Make a data table for each string tested, like the one below. The first entry in the data table is an example, so the numbers in your data table may look different. Continue reading the rest of the steps to understand the information you 'll record and calculate. You will be calculating at what fraction of the string 's length each of the harmonics were heard.
3.Using the data table that looks like your fretboard, list all of the fret numbers where a harmonic was heard (all the filled-in
Bibliography: Macfarlane, P. (2007). Lesson 46: Harmonics. Retrieved October 3, 2010, from http://www.guitarlessonworld.com/lessons/lesson46.htm Lorange, K Audacity Developer Team. (2000, May). The Free, Cross-Platform Sound Editor. Retrieved October 19, 2010, from http://audacity.sourceforge.net/ National Center for Education Statistics (n.d.) Strong,k (2010). science buddies. Retrieved from http://sciencebuddies.com/ Rock It Out Loud