A double reed instrument produces sound by vibrating two thin pieces of cane against each other. The most common examples are the oboe, bassoon, and English horn, all staples of the modern orchestra. What makes these instruments distinctive is both their bright, penetrating tone and the unusual way that tone is created.
How a Double Reed Works
A double reed is made from two symmetric blades of cane, tied together so that a narrow opening remains between them. When a player blows air between the blades, they vibrate rapidly, opening and closing like a tiny valve. This controls the flow of air entering the instrument’s tube, or bore, setting the air column inside into vibration and producing sound.
What makes double reeds acoustically interesting is that the two blades often close completely during each vibration cycle. This “beating” action generates a rich set of high harmonics, which is why double reed instruments have that characteristically bright, reedy timbre that cuts through an orchestra. The reed also acts as an amplifier: when a small pressure wave bounces back up the bore and reaches the reed, it nudges the opening slightly wider, letting in more high-pressure air from the player’s mouth. That extra air creates an even larger wave heading back down the bore. The reverse happens with low-pressure waves, which push the blades closer together. This feedback loop is what sustains the sound.
What Double Reeds Are Made Of
Nearly all double reeds are made from Arundo donax, a tall perennial grass native to Asia that now grows widely across the Mediterranean. The cane is harvested, dried, and then gouged to remove the soft inner layers. For a double reed, the prepared strip of cane is shaped along the sides, folded lengthwise, and bound to a small metal tube (called a staple) with waxed thread. Both sides are then carefully scraped to control thickness, and the folded tip is cut open to create the gap the player blows into.
This scraping process is where much of the craft lies. Small differences in thickness across the blade change how easily the reed vibrates, how stable the pitch is, and how the instrument responds at different volumes. Many professional oboists and bassoonists make their own reeds, spending hours adjusting them. A reed that’s too hard forces the player to use excessive air pressure, which can cause fatigue and, in extreme cases, circulation problems in the head and neck.
Once a reed is being played regularly, it becomes sensitive to humidity and altitude. Dry conditions can make cane stiff and unresponsive, while excess moisture can make it too soft. Unplayed cane, on the other hand, is remarkably stable. Reeds stored dry for 20 years have been reported to play without noticeable degradation. The clock starts ticking once they get wet.
The Oboe
The oboe is the most recognizable double reed instrument and the one that typically tunes the orchestra. It has a narrow conical bore, meaning the tube gradually widens from the reed to the bell. This conical shape, combined with the double reed, gives the oboe its focused, singing quality. The body is traditionally made from African blackwood (also called grenadilla), a dense hardwood that contributes to the instrument’s projection and tonal clarity.
Oboists place the reed directly between their lips, using precise muscle control (called embouchure) to manage pitch, dynamics, and tone color. Because the reed opening is so small, very little air actually passes through the instrument. Oboists often have the opposite problem from flutists: rather than running out of breath, they run out of time to exhale stale air. Long rests in orchestral parts sometimes exist specifically so oboists can breathe out.
The English Horn
Despite its name, the English horn is neither English nor a horn. It’s essentially a larger, lower-pitched relative of the oboe, sounding a fifth below it. The instrument is made from the same African blackwood as the oboe but is noticeably longer and features a bulb-shaped bell that gives its tone a warmer, more mellow character compared to the oboe’s brighter edge.
At the top of the English horn sits a curved metal tube called a bocal, which connects the reed to the body. The reed itself is larger than an oboe reed and attached via a metal tube called a staple. The English horn entered the orchestra around 1750. Before that, J.S. Bach used it under the name “oboe da caccia” (hunting oboe), since its curved shape made it practical to play on horseback.
The Bassoon
The bassoon is the bass voice of the double reed family and one of the largest standard woodwinds. Its bore is conical, like the oboe’s, but the tube is so long (roughly 2.5 meters) that it doubles back on itself inside the instrument’s body, giving the bassoon its distinctive tall, narrow profile. The body is made from maple, heavily varnished to protect against moisture.
The bassoon’s range is enormous, spanning roughly three and a half octaves, and its tone shifts character dramatically across that range. Low notes are dark and resonant, middle notes warm and lyrical, and high notes can sound thin or even comic, a quality composers have exploited for centuries. In orchestral writing, the bassoon serves both as a bass line instrument and as a solo voice.
How Double Reeds Differ From Single Reeds
Single reed instruments like the clarinet use one blade of cane that vibrates against a solid mouthpiece. Double reeds use two blades vibrating against each other with no mouthpiece at all. This difference in construction changes almost everything about how the instruments sound and feel to play.
Because double reeds close completely during each vibration cycle, they produce a wider spread of harmonics than single reeds typically do. This is what gives the oboe and bassoon their distinctive brightness and edge. The clarinet, by contrast, has a mellower, more rounded tone partly because its cylindrical bore emphasizes odd-numbered harmonics while suppressing even ones. Double reed instruments all use conical bores, which support both odd and even harmonics more evenly.
From a player’s perspective, double reeds demand more precise lip control and generally require higher air pressure to sound properly. The margin for error is smaller. A slightly misadjusted embouchure on a clarinet might produce a dull tone, but the same kind of slip on an oboe can produce a loud squeak, because the reed’s own natural vibration frequency takes over if the player’s lips aren’t damping it correctly. This is one reason double reed instruments have a reputation for being among the most difficult woodwinds to learn.
Double Reeds Beyond the Orchestra
The oboe, English horn, and bassoon are the double reeds most Western listeners encounter, but the double reed principle appears in instruments across the world. The Middle Eastern zurna, the Indian shehnai, the Chinese suona, and the Armenian duduk all use paired vibrating blades to produce sound. Some of these instruments predate European oboes by centuries.
In the formal classification system used by musicologists (the Hornbostel-Sachs system), all these instruments fall under category 422.1: reedpipes with double reeds, defined as pipes using paired lamellae that periodically open and close to control airflow. Whether it’s a Baroque oboe or a folk shawm from North Africa, the underlying physics is the same: two thin blades of cane, buzzing together, setting a column of air into motion.