Topic and Purpose:
Have you ever watched little babies play with sound? They shriek and squeal as they experiment with their voices. As they grow older, they blow bubbles in their milk with a straw and laugh at the funny sound it makes, or beat on pots and pans to see what kinds of clinks and clanks they can get out of them. Older still, they put cards in the spokes of their bikes, just to enjoy the rat-a-tat sounds as the wheels go round.
Like most children, musicians love to play with sounds, too. No matter what instruments they play, musicians love to "push the limits" to see what new strange or beautiful sounds they can get their instrument to make. Most instruments are held or played in a "standard way," but by varying the way an instrument is held, plucked, strummed, bowed, or breathed into, or by adding accessories, an instrument is often capable of a new sound—a new voice. This increases the richness and variety of the musical experience.
Guitars are no exception to this musical variety. Most people are familiar with watching someone strum a guitar, or play a wild solo at rock concert, but a guitar has a greater range of musical expression than this. For instance, the body of the guitar can be thumped or tapped, while playing the strings, to imitate drums, or to accompany the clicks from dancing shoes (flamenco style). A finger placed on the fretboard of the guitar, to play a note, can be pushed up slightly. This bends or stretches the note, giving the impression of crying or yearning (as in country or blues styles). Or, a finger from the left hand on the fretboard of the guitar can be vibrated rapidly from side to side, causing the pitch to change slightly, up and down, which gives the note a classical, singing style (called vibrato). Background:
This experiment is to identify the locations of harmonics on an acoustic guitar and relate them to guitar string lengths.
-What are the main parts of an acoustic guitar?
-When a guitar is held in the standard position, what are some ways the left hand can influence the sound that a guitar makes? What about the right hand? -Why do a harmonic and a plucked open string sound so different? -How would you play a harmonic on a guitar?
Manipulated Variables: Guitar Fretboard
Responding Variables: Plucking, Strumming and a Tuner
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-size
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. 1.Continuing on with the same string, repeat step 1 for all frets, from fret 11 down to fret 1. 2.Repeat steps 1–2 for two additional 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...