When Madonna picked up a ballpoint pen and wrote "Music makes the people come together", she probably hadn't just seen what I've just seen: a chap pulling up at traffic lights while playing Skrillex at a volume so arse-rumblingly intense that his car shook, tectonic plates shifted, sedimentary rock metamorphosed, and a woman in a blue tracksuit dropped her shopping.
His friend opened the passenger door and the emerging blast of sound was like someone taking a duvet off the top of Milton Keynes Bowl. Bystanders were united in their desire for him to turn the bloody thing off, so in that sense the music did make "the people come together". But this wasn't Madonna's utopian vision. This was purgatory with a newly installed 1,000W subwoofer.
Understanding music's capacity to irritate is part of becoming an adult, or so I thought. When I was a spotty teen it was common for young men to wander about carrying a boombox playing The Jesus and Mary Chain or Public Enemy or The Fall, in the forlorn hope that a stranger would congratulate them. This was their proud display of musical preference, like wearing a really noisy T-shirt. But eventually they realised that their cultural evangelism was merely a lump of noise pollution moving around shopping arcades at approximately two miles an hour. Today's equivalent, I guess, is a teenager blasting Swedish House Mafia from their mobile phone on the 76 bus. They'll grow out of it, right?
Not necessarily. Some people retain a lifelong compulsion to foist their musical predilections upon others, whether it's a Celine Dion-obsessed neighbour embroiled in a deafening quest to establish whether "The Power of Love" is better than "Think Twice", or a coach driver blasting out "I Still Haven't Found What I'm Looking For" while singing along vaguely ("I hah sheh, smay the splountains") or the busker at Angel Tube station in north London who plays the first 12 bars of "In the Mood" by Glenn Miller in a seemingly endless loop, like some malfunctioning swing-era robot.
This realisation has made me so ridiculously sensitive to the music people might like or dislike that I know I'd be the world's most feeble DJ. If Madonna said, "Hey, Rhodri Marsden, put a record on, I want to dance with my baby," I'd reply, "OK, Madonna, not a problem – but could you be more specific?"