<P> A reed is a thin strip of material which vibrates to produce a sound on a musical instrument . The reeds of most woodwind instruments are made from Arundo donax ("Giant cane") or synthetic material; tuned reeds (as in harmonicas and accordions) are made of metal or synthetics . Musical instruments may be classified according to the type and number of reeds used . </P> <P> The earliest types of single - reed instruments used idioglottal reeds, where the vibrating reed is a tongue cut and shaped on the tube of cane . Much later, single - reed instruments started using heteroglottal reeds, where a reed is cut and separated from the tube of cane and attached to a mouthpiece of some sort . By contrast, in an uncapped double reed instrument (such as the oboe and bassoon), there is no mouthpiece; the two parts of the reed vibrate against one another . </P> <P> Single reeds are used on the mouthpieces of clarinets and saxophones . The back of the reed is flat and is placed against the mouthpiece, the rounded top side tapers to a thin tip . These reeds are roughly rectangular in shape except for the thin vibrating tip, which is curved to match the curve of the mouthpiece tip . All single reeds are shaped similarly but vary in size to fit each instrument's mouthpiece . </P> <P> Reeds designed for the same instrument may look identical to each other, but may vary in thickness ("hardness" or "strength"). Hardness is generally measured on a scale of 1 through 5 from softest to hardest . This is not a standardized scale and reed strengths vary by manufacturer . The thickness of the tip and heel and the profile in between affect the sound and playability . Cane of different grades (density, stiffness), even if cut with the same profile, will also respond differently. This is due to the natural differences in the density of the cane fibers . </P>

Where does the reed go on a clarinet