Abstract:
A musical drum comprised of a drumshell and a drumhead, which includes a composite of tonal modifiers acting synergistically for dampening drum sounds by eliminating high frequencies and overtones. The tonal modifiers include a first tonal modifier comprised of synthetic material, a second tonal modifier bonded to the synthetic material in overlaying relation, a third tonal modifier positioned upon the second tonal modifier in overlaying relation, and a fourth tonal modifier bonded to the central portion of the third tonal modifier in overlaying relation, the combination of which cooperate to break down the various levels of harmonics to their purest form resulting in a unique sound and vibrational experience provided in a therapeutic context for the well-being of a person.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a musical drum and, more particularly, to a musical drum incorporating a combination of cooperative tonal modifiers which produce levels of vibrations and resulting sounds that are uniquely therapeutic to the human body. 
     2. Description of the Prior Art 
     When a drumhead is struck with an object, it vibrates in modes, which enable the conjugation of certain frequencies. The lowest mode of vibration is its simplest form, as the film material used to fabricate the drumhead tends only to vacillate without any twisting or lateral motion. The only nodal point in this mode, which is the area with the least amount of vibration, is the outer perimeter of the drumhead. 
     The second mode tends to split the drumhead into halves, thereby creating higher partials or overtones. 
     The third mode of vibration divides the drumhead again into quarter-circle sections which, in turn, creates additional higher frequencies and overtones. 
     With only these three modes of vibrations in their most simple form (excluding, for example, the sound of a mallet striking the head, which will vary with the hardness and weight of the mallet on the head) a conventional drumhead can easily produce a complex series of harmonics. The principle objective of the present invention is to break down the various levels of harmonics and reduce other extemporaneous sounds to their purest form with the use of certain tonal modifiers, specifically the composite of tonal modifiers integral to the drumhead of the present invention, and to use the resulting unique sound in a therapeutic context for the well-being of a person. 
     A drum can be played by one person or many persons simultaneously. Ordinarily, the simultaneous playing of a single drum by a group of players is impractical, particularly in an indoor setting, given that the sounds that are generally produced would be excessively loud and complex and rhythmically and musically antithetical to a pleasing experience. Certain drums, such as, for example, the so-called Pow Wow drum with its deep sidewalls, do not permit the players to sit sufficiently close enough to a drum positioned horizontally. 
     The group playing of a single drum was common among Native American tribes. But since the majority of the drums then were relatively small, it was necessary for the players to sit at a distance from the drum and to use a single mallet or stick to strike the drumhead. Since the drums were played outdoors, there was no need to be concerned about the loudness of the sound volume, as quietness was not a requisite. 
     In the modern world, music therapists use percussion instruments, including various versions of the musical drum, in group settings and often in quiet institutions, such as hospitals and nursing homes. Within this context, there is a need for a single drum that many may comfortably share, whether, for example, while sitting in a conventional chair or wheelchair, or standing, to ensure the experience of the healing benefits of the therapeutic sounds and vibrations produced. Accordingly, the present invention fulfills a long felt need by providing a drum with a vibratory membrane (i.e. the drumhead), which incorporates a rare combination of tonal modifiers that act synergistically to break down the various levels of harmonics, as described, to suppress overtones and produce a unique therapeutic sound. This therapeutic sound comprises a single dominant low frequency sonic wave experienced throughout the human body when a person is sitting or standing in close proximity to the drum. 
     SUMMARY OF THE INVENTION 
     The present invention provides a musical drum comprised of a drumshell and a drumhead, which includes a composite of tonal modifiers acting synergistically for dampening drum sounds by eliminating high frequencies and overtones. The tonal modifiers include a first tonal modifier comprised of a two-ply synthetic material, a second tonal modifier bonded to the two-ply synthetic material in overlaying relation, a third tonal modifier positioned upon the second tonal modifier in overlaying relation, and a fourth tonal modifier bonded to the central portion of the third tonal modifier. 
     In the preferred embodiment of the present invention, the first tonal modifier is comprised of polyester, typically a two-ply polyester, such as Mylar®, the second tonal modifier is comprised of a semi-rigid polyvinyl chloride sheet material, the third tonal modifier is comprised of a woven cotton fabric material and the fourth tonal modifier is comprised of a semi-rigid polyvinyl chloride sheet material, though smaller in diameter than the diameter of the sheet material comprising the second tonal modifier. 
     Accordingly, it is an object of the present invention to provide a musical drum with an improved drumhead comprised of a composite of tonal modifiers for dampening drum sounds. 
     It is another object of the present invention to provide a musical drum with an improved drumhead comprised of a composite of cooperating tonal modifiers for dampening drum sounds by eliminating high frequencies and overtones. 
     Another object of the present invention is to provide a musical drum with an improved drumhead that, in the process of suppressing overtones, produces a therapeutic sound. 
     Another object of the present invention is to provide a musical drum with an improved drumhead that produces a therapeutic sound experienced throughout the human body for providing a feeling of wellness. 
     Another object of the present invention is to provide a musical drum with an improved drumhead that produces a single dominant low frequency sonic wave that can be felt by a person standing or sitting nearby the drum. 
     Another object of the present invention is to provide a musical drum with an improved drumhead that can be played and enjoyed by one person alone, or by many persons simultaneously. 
     Another object of the present invention is to provide a musical drum with an improved drumhead that provides a continuous pulsating massage-like experience to persons sitting or standing adjacent the drum or sitting or lying beneath the drumhead. 
     Another object of the present invention is to provide a musical drum with an improved drumhead that easily enables a person sitting up close to the drumhead the freedom to position the legs beneath the drumhead and comfortably play the drum. 
     Another object of the present invention is to provide a musical drum with an improved drumhead that is easy and cost effective to manufacture. 
     Other objects and advantages of the present invention will become apparent in the following specifications when considered in light of the attached drawings wherein the preferred embodiment of the invention is illustrated. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of the musical drum in accordance with the present invention. 
         FIG. 2  is a cross-sectional view of the drumhead portion of the musical drum in accordance with the present invention. 
         FIG. 3  is a perspective view of a musical drum with a center pedestal stand in accordance with the present invention. 
         FIG. 4  is a cross-sectional view of the hub and post components used in conjunction with the pedestal stand to support the musical drum in accordance with the present invention. 
         FIG. 5  is a spectrum analysis of the sound frequencies (in hertz) produced by striking a drumhead having only a conventional single tonal modifier. 
         FIG. 6  is a spectrum analysis of the sound frequencies (in hertz) produced by striking a drumhead having a composite of cooperative tonal modifiers in accordance with the present invention. 
         FIG. 7  depicts a mallet striking a drumhead near its edge and a spectrum analysis of the sound frequency attenuation when a drumhead is so struck in accordance with the present invention. 
         FIG. 8  depicts a mallet striking a drumhead near or at its center and a spectrum analysis of the sound frequency attenuation when a drumhead is so struck in accordance with the present invention. 
         FIG. 9  is a perspective view of a musical drum in accordance with the present invention shown with a wheelchair positioned in close proximity. 
         FIG. 10  is a perspective view of a musical drum in accordance with the present invention shown with several persons sitting and standing in close proximity playing the drumhead with a hard object by striking at or near its center. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention will be described in more detail with reference to the preferred embodiment shown in  FIGS. 1 through 10 . 
     Musical drum  10  is comprised of drumshell  12 , including exterior sidewall  54  and interior sidewall  56 , and drumhead  14 , which consists of first tonal modifier  20 , second tonal modifier  22 , third tonal modifier  24 , and fourth tonal modifier  26 . The composite of uniquely cooperative tonal modifiers  20 ,  22 ,  24 , and  26  are provided for dampening sounds produced by musical drum  10 , particularly drumhead  14 , by eliminating high frequencies and overtones in accordance with the present invention. 
     The preferred embodiment of the present invention consists of a composite of the following: tonal modifier  20  is comprised of a polyester material, typically two-ply, such as Mylar®, which includes first ply  30  and second ply  32 , which float, and thus, dampen, reciprocally. The durability of tonal modifier  20  is enhanced due to the thickness of overlapping plies  30  and  32 . The preferred thickness of the polyester film is 0.0075″. Tonal modifier  20  achieves the initial dampening of the higher partials or overtones. 
     Second tonal modifier  22  is comprised of a semi-rigid polyvinyl chloride sheet material, the preferred material with a thickness of 0.010″. Tonal modifier  22 , which is attached to tonal modifier  20  by adhesive  23  or some other suitable bonding agent is usually about 0.007″ thick. The bonding of tonal modifier  22  to tonal modifier  20  greatly enhances the rigidity of drumhead  14  and, thus, removes the twisting motion, which prevents drumhead  14  from dividing into half or quarter sections. The added weight of tonal modifier  22 , or “mass loading” as it is sometimes called, also slows the vibrations and lowers the pitch of drumhead  14 . 
     Third tonal modifier  24  is comprised of a woven cotton fabric material, such as the material commonly known as duck cloth, the preferred material for this tonal modifier component. Woven duck cloth is extremely supple and, depending on the actual thread count, denier, and weave pattern will easily drape (float, not bonded) over attached tonal modifier  20  and  22 , causing it to further suppress sound. Tonal modifier  24  is generally a high tenacity heavy plain woven fabric that is strong and long lasting and very appropriate for use with drumhead  14 , which is being struck repeatedly with the hands or a hard object, such as a drumstick (not shown) or mallet  58 . Tonal modifier  24 , in combination with attached tonal modifiers  20  and  24 , builds on the initial two-ply polyester concept whereby the combination of attached tonal modifiers  20  and  22 , and tonal modifier  20  are not bonded, thereby creating phase interference between the two vibrating members. This creates mass loading and consequently contributes to the lowering of the pitch of drumhead  14 . Additionally, tonal modifier  24  is saturated with water-based sealer  28 , which is known by the trademark Haloflex™, the preferred sealer for this purpose, so that the fabric surface can be sealed and easily cleaned. Typically, the material comprising tonal modifier  24  is 0.024″ thick. Applied sealer  28  soaks into the cotton weave of the material comprising tonal modifier  24  and also forms a thin film on the top and bottom surfaces, respectively. The combined thickness of the two, i.e. the cotton fabric and sealer, is 0.034″. 
     Fourth tonal modifier  26 , in its preferred form, is comprised of a semi-rigid polyvinyl chloride sheet material, though smaller in diameter than the sheet material used to fabricate second tonal modifier  22 . Tonal modifier  26 , which is bonded to tonal modifier  24  by adhesive  23 , covers approximately 40% of the overall diameter of drum  10 , and offers additional mass loading of drumhead  14 , but mostly only in its center portion  16 . The weight of the material comprising tonal modifier  26  enhances the vacillating motion of the vibrating member over a greater period of time. The material comprising tonal modifier  26  has a thickness of 0.010″. Adhesive  23 , after the application to tonal modifier  26 , is approximately 0.007″ thick. 
     A tonal modifier incorporated into a musical drumhead normally affects the sound volume at the highest frequencies, as shown in  FIG. 5  and in  FIG. 6  in accordance with the present invention.  FIG. 5  shows a spectrum analysis of musical drum  10  ( 40 ″ in diameter) with drumhead  14  having only a conventional single tonal modifier comprised of two plies ( 30 ,  32 ) of a suitable synthetic material, such as polyester. With time shown in seconds and frequency in hertz, the volume level of sound produced when drumhead  14  is struck reaches its highest level. 
       FIG. 6  shows a spectrum analysis of musical drum  10  ( 40 ″ in diameter), such as, for example, drumhead  14  with a composite of synergistically acting tonal modifiers  20 ,  22 ,  24  and  26  in accordance with the present invention. Shown with time in seconds and frequency in hertz, the volume level of the unique sound produced when drumhead  14  is struck decays at a much greater rate than the previous example shown in  FIG. 5 , which produced merely a single dominant low frequency of sound. 
     With all four tonal modifiers  20 ,  22 ,  24  and  26  combined and cooperating, as above described, the frequency attenuation is at its highest when drumhead  14  is struck near its outermost edge  57  (see  FIG. 7  and designations A, B and C) and at its lowest (i.e. the lowest notes are loudest and more apparent) when drumhead  14  is struck nearest or slightly off its center  59  (see  FIG. 8  and corresponding designations A 1 , B 1  and C 1 ). 
     Stand  40  used to support drum  10  of the preferred embodiment of the present invention is the pedestal type, as shown in  FIGS. 1 and 4 . Stand  40  is attached to drumshell  12  utilizing hub  50 , as shown in  FIG. 3  and in cross-section in  FIG. 4 . Hub  50  around its periphery is connected to a plurality of support spokes  53  that radiate to engage interior sidewall  56  of drumshell  12  where each is attached equidistantly using any suitable attachment means, including, without limitation, rivets  61 , or screws, bolts, fasteners and heavy staples (not shown), which may also be utilized for attaching spokes  53  to hub  50 . Pedestal base  42  and vertical post  46  are connected by inserting tapered bottom end  44  of vertical post  46  into tapered conforming opening  48  and tapered top end  45  into conforming tapered opening  47 . Both bottom ends  44  and  45 , and respective conforming openings  47  and  48  are tapered to establish a tight, stable connection making it normally unnecessary to use tools to attached drum  10  to pedestal stand  40 . 
     The drum shown in  FIGS. 1 ,  3 ,  9  and  10  can be arranged so that four or more players  60  can sit or stand around the drum comfortably and play it with their hands or with the use of mallets or the like. The pedestal stand, the short depth of the drumshell and the absence of any outer drum support stands or hardware that would hinder their playing allows for a player in a wheelchair  62  to be a part of the group drumming experience as well. Additionally, with the drum in a horizontal and relatively high position, children and smaller adults (not shown) can literally sit or lie down under drum  10  and feel the sound waves as drum  10  is being played. Since sound waves move in a simple vacillating motion similar to a loudspeaker, most, if not all, of the waves will strike the person directly, resulting in a continuous pulsating massage-like experience. 
     The body shape of the drum will also determine which frequencies are enhanced, dampened or in some cases completely eliminated. For instance, a bowl-shaped drum, such as an African djembe, will accent certain bass frequencies because it acts as a tuned resonator. Other straight-sided drums will do the same if the length of the drumshell is extended sufficiently so that the air inside can be contained enough to vibrate. Short depth drums, on the other hand, do little to create additional tonal properties. The short shell is used more for its framework to house and support the drumhead and increase the sustain of the drumhead if the drumshell frame is suspended and free to vibrate. Preferred drum diameters for drum table  10 , the example shown in the drawings, are 22″, 30″, and 40″ with the thickness of drumshell  12  of ½″ to ¾″. Drumhead  14 , more particularly the polyester film of tonal modifier  20  and the woven duck cloth of tonal modifier  24 , is tensioned over drumshell  12  and held in place against exterior sidewall  54  with staples  51 , rivets or any other suitable attachment means (not shown). 
     While the invention is described in connection with a certain preferred embodiment, it is understood that it is not intended to limit the invention to that particular embodiment. Rather, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.