The present invention relates generally to stringed musical instruments and more specifically to improvements in the design of stringed musical instruments, particularly guitars.
Stringed musical instruments have been in existence for thousands of years, with instruments such as the lyre dating to at least 900 BC. Indeed, early Biblical writings are replete with references to the harp, lute, and lyre. The guitar is a member of the lute family of instruments and are believed to have originated in Europe in the 1400s. Today's modern guitar is believed to have originated in Spain in the mid-1800s by guitar maker Antonio de Torres Juarado. Modern guitars may be acoustic, where the body of the instrument amplifies the sound created by the vibration of the strings, or electric, where the vibration of the strings is converted to electrical signals and amplified by external means. Common parts of a guitar comprise a body which may be hollow or solid, a neck which includes a top surface called the fingerboard containing raised metal strips called frets, a headpiece located at the end of the neck containing a means for adjusting the tension of the strings called tuning keys, and a set of strings that can vary in number that are stretched from the body to the headpiece and are attached to the tuning keys.
The vibrations of the strings of an acoustic guitar resonate in the body, or sound box, which is generally hollow. The body is typically made of hardwoods of various types. Different woods may be used for the sides and back than are used for the top of the body. Each type of wood lends a different tone to the sounds produced. The neck is usually made of a structurally strong wood in order to withstand the forces exerted on it by the tensioned strings without warping. Strings are generally either nylon or steel, and the choice of string material is often related to the type of music being played.
Early electric guitars were simply acoustic guitars fitted with electrical pickups, a device similar to a microphone in that it converts string vibrations into electric signals that are reproduced as sound through an amplifier and speaker. These instruments eventually evolved into solid-body instruments in order to solve problems related to vibrations and undesirable noise. The first solid-body guitars were developed in the United States in the 1930's, with the earliest examples being Hawaiian, or slide, guitars. Most electric guitars today follow either the Les Paul design created for the Gibson Guitar Company, or the Stratocaster design of Leo Fender.
The playing of the guitar involves strumming or plucking the strings with the fingers of one hand or a plectrum, commonly known as a pick. Different musical notes or chords are created by pressing down on the strings at the frets with the fingers of the other hand, effectively shortening the vibrating length of the string. The playing of a slide guitar involves pressing down on the strings with a cylindrical object called a slide, rather than the musician's fingers. As with all stringed musical instruments, the playing of a conventional guitar involves the use of only a portion of each string. The portion of the string above the point of contact, whether contact is made by the musicians fingers or a slide, is effectively “shut off” from producing musical tones.
The playing of a guitar involves pressing down on one or more strings at one or more of the frets along the fingerboard to effectively shorten the string. The string is then plucked or strummed to induce vibration in the string. By pressing the string down onto one of the frets, the portion of the string above the pressure point is effectively “shut off” and produces no appreciable amount of sound. The present invention allows the portion of the string on both sides of the pressure point to be played, thus creating a richer and fuller array of musical tones that cannot be achieved with conventional stringed instruments.
One embodiment of the present invention has an elongated body with a generally flat top surface. Mounted on the top surface of the body are two fingerboards, each of which has its own set of frets. The two fingerboards are mounted end to end so that they form a generally continuous fingerboard and are collinear with one another. A number of strings are suspended parallel to one another over the fingerboards and are under tension. One end of the strings are secured to the body and the other end is attached to a mechanism that allows the tension of the strings to be adjusted. One fingerboard extends toward the secured end of the strings, and the other fingerboard extends toward the tension adjusting end of the strings. Thus, the fingerboards run parallel to the strings. The fret spacing of each fingerboard begins at the end where the two fingerboards meet. Thus, the fret spacing decreases on one of the fingerboards in the direction of the secured end of the strings, and decreases on the other fingerboard in the direction of the tension adjusting end of the strings. One or more electrical pickups are mounted at the secured end of the strings and one or more electrical pickups are mounted at the tension adjusting end of the strings.
The frets are attached to the top surface of the fingerboard and are oriented essentially perpendicular to the fingerboard and the strings. The frets extend above the top surface of the fingerboard. In another embodiment of the present invention, the frets are replaced by tone indicating markings on the surface of the fingerboard. These markings are flush with the top surface of the fingerboard, creating an essentially smooth surface along the entire length of the fingerboard.
In yet another embodiment of the present invention, the body of the musical instrument is hollow. The hollow body contains a first hole in the top surface located under the strings between the end of one of the fingerboards and the secured end of the strings. A second hole is located in the top surface of the body, also under the strings but between the end of the other fingerboard and the tension adjusting end of the strings. One embodiment of the hollow body musical instrument includes fretted fingerboards as described previously. In still another embodiment of the hollow body musical instrument, the fingerboards include tone indicating markings as described previously.
These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:
It is understood that the embodiments described herein are intended to serve as illustrative examples of certain embodiments of the present invention. Other arrangements, variations, and modifications of the described embodiments of the invention may be made by those skilled in the art. No unnecessary limitations are to be understood from this disclosure, and any such arrangements, variations, and modifications may be made without departing from the spirit of the invention and scope of the appended claims.
Referring in detail to the drawings, wherein like numerals represent like elements in multiple drawings, in
In
The frequency of vibration for the first five harmonics of a tensioned string are shown in
The unique ability of the present invention to produce a wide array of musical notes and tones is shown in
One embodiment of the present invention comprises a fingerboard with frets. This embodiment is played in part like a conventional guitar where one or more fingers of one of the musician's hands press down one or more of the strings at the appropriate frets such that when the strings are plucked or strummed a certain note or chord is played. A unique aspect of the present invention is that the strings can be plucked or strummed on either side of the point where the strings are pressed down, enabling an expanded array of musical tones to be created.
Another embodiment of the present invention comprises a fingerboard with markings on the top surface rather than frets such that the top surface of the fingerboard is smooth. This embodiment facilitates the playing of the instrument in the manner of a slide guitar, also known as a Hawaiian guitar. The slide, typically a metal cylindrical object, is placed across the strings and is used to press down the strings while strumming or plucking to form musical tones. As the slide is moved up or down the strings, the changing length of the vibrating portion of the strings changes the frequency of vibration. If the slide is moved in one direction, the length of the vibrating portion of the strings is shortened, resulting in an increasing pitch of the sound produced. Alternately, moving the slide in the opposite direction increases the length of the vibrating portion of the strings, causing the pitch to decrease. In the present invention, the strings can be plucked or strummed on both sides of the slide. Thus, by moving the slide in one direction, the musician can simultaneously create sounds of both increasing and decreasing pitch. The array of musical tones that can be produced with the present invention is unique among stringed musical instruments.
The wide array of musical tones produced by the present invention can be portrayed mathematically. When a string of the present invention is pressed down, two segments of string are effectively created, each shorter in length than the original string. If we let the variable “n” equal the ratio of the length of one of the segments to the length of the original string, the frequency of vibration of this shortened segment of string (relative to the fundamental frequency of the original string) is represented by 1/n. Similarly, the ratio of the length of the second shortened segment of string to the length of the original string is represented by 1−n, and the frequency of vibration of the second segment of string (relative to the fundamental frequency of the original string) is represented by 1/(1−n). This frequency ratio defines musical (frequency) intervals. For example, the perfect fourth inverval occurs when 1/n=4/3, and the perfect fifth interval occurs when 1/n=3/2.
Thus, the frequency interval of the first segment of the shortened string to the second segment of the shortened string is represented by n/(1−n). In other words, n/(1−n) is the frequency interval between the first and second segments of the string when the segments are played simultaneously. Since the relationship of the string segments is symmetrical, (1−n)/n represent the same interval only going down the scale rather than up the scale.
The ability of the present invention to produce unique musical tones can begin to be seen when the ratio of the length of the first string segment to the second string segment is an integer. When the ratio is 2 (that is, the length of the first string segment is twice that of the second string segment), n is 1/3 and 1−n is 2/3. When n is 1/3, the frequency of vibration is an octave and a perfect fifth interval above the harmonic frequency and when n is 2/3, the frequency of vibration is a perfect fifth interval above the harmonic frequency. This octave separation between the frequency of vibration of these two segments imparts a harmonious sound when played together. When the ratio is 3 (that is, the length of the first string segment is three times that of the second string segment, n is 1/4 and 1−n is 3/4. The frequency of vibration of these two string segments will be separated by an octave and a perfect fifth interval, again producing a harmonious combination. A 4/3 perfect fourth interval can be created by the two string segments when n is 3/7 and 1−n is 4/7 (that is, (1−n)/n=(4/7)/(3/7)=4/3).
However, when the ratio of (1−n)/n is a rational number instead of an integer, notes are created that diverge from the intervals of the traditional music scale. Table 1 shows the ratios of the first 19 half steps in a 12-note scale, which is approximated by a logarithmic scale such that the ratio of the frequency of any note that is “x” half steps above the fundamental frequency to the fundamental frequency is given by the equation 2(x/12). Hence, whenever x is a multiple of 12, the note rises an octave (the frequency doubles). As shown previously, the interval between the frequencies of the two string segments is a perfect fourth when n is 3/7 and 1−n is 4/7. The “note” of each of these segments relative to the fundamental frequency of the string is 7/3 (2.33333) and 7/4 (1.75000), respectively. These notes fall between the half steps 14 and 15 of the table for 7/3 and between half steps 9 and 10 for 7/4. While such semitones may sounds discordant when played on other musical instruments, they have a pleasant, harmonious sound when played on the present invention.