Not everyone fits aftermarket exhausts to their motorcycles purely for performance gains. Rather than horsepower, some riders chase decibels with their accessories. But while loud pipes aren’t safety devices, more noise isn’t necessarily the only goal. As Honda Brasil recently demonstrated, motorcycle exhausts can also make an excellent orchestra.

Honda Brasil turned a São Paulo rooftop into a motorcycle concert hall

Rooftops make for great rider meetup events, but they’re usually not concert halls. However, that didn’t stop Honda Brasil from putting on a concert on one São Paulo rooftop. Only instead of guitars, violins, or trumpets, the concert was played on Honda motorcycles and scooters.

The impromptu ‘concert’ is part of a new Honda Brasil ad campaign fittingly dubbed ‘The Motor Song,’ RideApart reports. Released on July 27^th, Motorcyclist Day, it features local Honda motorcycle and scooter riders directed by a conductor. And as you’ll discover below, ‘directed’ is indeed the right word.

Honda and ad agency Publicis Brazil weren’t the only two companies involved in the motorcycle ad. Besides film company Fuelture, audio production company Hefty came onboard to help tune the motorized orchestra. To make a viable song, Hefty had to analyze the engines’ musical notes to understand how different displacements affected the timbre, RideApart explains. Hefty then had to work out how each engine revved to get the timing right.

But in the end, that effort paid off.

‘Well-tuned’ doesn’t just mean high horsepower

It might seem odd that a Honda motorcycle, or indeed any bike, can serve as an ersatz woodwind instrument. But in reality, engineers tune engines and exhausts for sound and emotion as much as horsepower. Case in point, the famous Harley-Davidson air-cooled V-twin ‘potato’ sound. And these concepts aren’t mutually exclusive, either.

Your motorcycle’s exhaust system, from the headers to the muffler, is designed to vent waste gases away from the combustion chambers. If that didn’t happen, your engine would make less power, run less efficiently, and even choke and die due to excessive gas backpressure. But a well-designed motorcycle exhaust system doesn’t just let these gases escape quickly. It also uses the energy of those gases to pull in fresh air and fuel into the engine in a process called ‘scavenging,’ Cycle World explains.

Engineers modify backpressure and scavenging by playing around with the length, radius, and overall shape of your motorcycle’s exhaust headers and pipes. But remember, exhaust gases move as pressure waves—in other words, sound waves. So, changing a pipe’s dimensions also changes how sound travels through it. Plus, your motorcycle exhaust pipes aren’t just vibrating individually; they’re resonating with each other, Car and Driver explains. And not all resonance is pleasant to the ear.

That’s why removing your motorcycle’s muffler is a bad idea. Besides ‘muffling’ the overall exhaust volume, a motorcycle muffler also has internal baffles that naturally cancel out unwanted frequencies. Removing the muffler will make your bike louder, but it will also likely make it sound worse. Plus, because removing the muffler changes the exhaust setup, it can damage engine internals and make it run hot, Motorcyclist says.

Your bike might not make music, but a quality motorcycle exhaust can change its tone

Admittedly, the shape of your motorcycle exhaust pipes isn’t the only factor that affects your bike’s sound. The crankshaft, which determines the engine’s firing order, also plays a significant role. That’s why the Shelby Mustang GT350 sounded Ferrari-like: rather than a cross-plane crank, it had a flat-plane crank.

However, swapping your stock muffler for an aftermarket slip-on muffler will change how your motorcycle exhaust sounds, RevZilla reports. Plus, while aftermarket mufflers add minimal horsepower at best, they are usually lighter than the stock ones. Prices vary based on your bike’s make and model. But know that plenty of suppliers, including Akrapovic and Termignoni, support Honda motorcycles.

So, as long as you comply with local noise limits, feel free to make your own motorcycle symphony.

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