Pitch Vs. Frequency

• The perceived musical pitch produced by a guitar may not match the tone's frequency. Acousticians define frequency as the number of cycles, or vibrations, that an object experiences each second. Objects such as guitar strings that vibrate quickly produce high sounding tones, whereas slower rates of vibration produce lower tones. The volume and location of the sound may distort a listener's perception by making the tone seem higher or lower than the actual frequency, or rate, of physical vibrations.
  
  

Guitar Acoustics

• Guitars create musical pitches when a player strums, plucks or strikes the strings. This initial gesture energizes each string, causing a wave-like motion that crosses the length the string. When the guitar string vibrates near the sound hole of a resonant guitar body, the open space in the inside of the guitar amplifies the hum created by the vibrating string. The pitch perceived by the listener relates to the length and width of the vibrating string. Guitarists create the pitches needed to play music by pressing down on the fretboard with a fingertip to change the length of a string.
  
  

Guitar Tuning and Range

• A traditional six-string classical guitar sounds pitches that cover more than three octaves. Traditional tuning, notated as E-A-D-G-B-E, begins two octaves below middle-C. Alternate tunings can extend the pitch range of the guitar. Dropped-D extends the lowest pitch to a D two octaves below middle-C, but retains the other five notes of traditional tuning. Another popular alternate tuning, nicknamed "dad-gad," lowers the total range of the guitar by a major second.
  
  

Electric Guitars

• Electric guitars can produce a seemingly unlimited assortment of timbres at extreme volumes by converting the physical energy of the vibrating guitar strings to electrical energy. Musicians can run this electrical signal through a complicated chain of effects pedals and computer software to create pitches that extend beyond the original acoustic capabilities of the instrument. These manipulations of tone and volume can create a collection of subjective pitch sensations that do not precisely correlate to the frequency, or vibration speed, of the guitar string that originally created the tone.