Does your knee play audiences a catchy, crackly tune every time you bend it? While fascinating, those pops and cracks could be a simple serenade of aging joints or a warning sign that your knee needs an immediate encore with a healthcare provider.

"Crepitus" is industry jargon for the grating sounds or sensations produced by your body's own bony orchestra – namely the friction between bone and cartilage. You’ll hear this natural melody in every joint but for some, the knee conducts the loudest symphony.

Knee crackles and pops and can serenade both young spry dubstep fans and golden oldies crooners alike. Sometimes, these noises arise when the air gatecrashes the joint lubricating fluid (the synovial fluid to insiders), creating a popping bubble choir. When the knee conducts a bend or a stretch, those bubbles burst into sound, but they're as harmless as a choral pop tune.

However, there may be situations where the knee symphony plays awry and suddenly the tune feels like it's "catching," punctuated with discomfort, swelling, redness, and even an enthralling performance of the knee-locking manoeuver. Horror-thriller aficionados take note, these could all be signs of the notorious meniscus tear: a gnarly plot twist where the cartilage cushion between the shinbone and thighbone is torn due to a traumatic injury or knee joint's rebellious stage performance.

Spotlight on knee crepitus, a sound effect from the underbelly of knee debauchery. This soundtrack flares up when the femur has taken the wrong stage steps or the kneecap decides to freeload on the knee joint. All these overlapping gigs can cause the knee cartilage to lose its shine and, eventually, wear off – resulting in catchy popping tunes during a rigorous stair-climbing session, a sprint uphill, or soulless, rigorous exercise.

Such overuse syndromes and joint missteps could lead to "runner's knee," also known as patellofemoral stress syndrome (PFSS) – a popular rock genre among long-distance runners. Still, it could gang up on someone with a bad fall record or an unfortunate participant in a car crash.

Talking about falls, knee crepitus is an early contender for the role of retirement anthem – a.k.a. knee osteoarthritis (OA). As age takes over the stage, knee cartilage gives its final performance, leading to stiffness and, ultimately, pushing the knee joint into forced retirement. Knee OA does a sneak release of the crepitus album that is chronically cool and comes with a side of chondromalacia patella– a catchy label for those who fancy softening and crumbling of the knee cartilage.

Those knee pops and cracks may not necessarily ferry a pain cargo to start with but could herald the onset of an overuse injury or osteoarthritis as the concert progresses. Thus, knowing whether your knee plays a harmless rhapsody or sounds the alarm bell for a serious condition could be the difference between a quick intervention and a long-term health condition.

So, next time you hear your knee play a catchy tune, take note. If your knee's live performance comes with any pain, discomfort, or other symptoms, give those joints backstage access to a healthcare provider. After all, no one likes a repetitive performance.