If I'm not swimming in the ocean I'm often walking along the seawall and, like so many other people these days, I'm usually listening to music at the same time. As I pass others coming and going I've noticed that most folks are using the same ear bud style headphones and they are either black or white in colour. White presumably being the colour of the Apple crowd, and black being that of the Android set. Of course it's hard to say with any certainty these days, given that everything is so interchangeable, and the devices people are listening to their music on could be either an iPod, cellphone or something else entirely.
Listening to music while walking has been around for a long time, at least since the 60's when the portable transistor radios first came out, and I got my first one in 1968 after saving up my paper route money. Back then it was only AM radio that was initially available, though it later expanded to FM as well, and there was only one earphone because AM sound was mono, not stereo. Curiously enough the size of the device then wasn't much different than the iPod or any of the new cellphones available now; it was something that could fit inside a shirt pocket.
Sony was the dominant portable transistor radio manufacturer in those days, and it also later came out with the famous Walkman that allowed people to listen to their own recorded music on a cassette tape and then, later still, on CDs. The next wave was the MP3 or digital media player, but this time it was Apple's iPod that really took control of the market and put something new into everyone's shirt pocket. By combining the MP3 player with a cellphone they also eliminated the need for people having to carry two devices around with them, three if you counted a camera. Other manufacturers quickly caught on, mostly powered by the Android operating system, and now the fashionistas of the world are divided into two main camps; Android or Apple.
One person's music is another person's noise and for that reason headphones are a blessing for everyone, even it means we are somewhat disconnected from other people around us and the sensory experience of wherever we happen to be walking. But, whether the music is meant to soothe, pump up the adrenalin, or simply help us escape, the appeal is universal, and the selection now available is almost limitless. The little device in your shirt pocket can play music from AM/FM radio stations, live streaming of any genre off the Internet, and of course whatever music you've already downloaded.
As popular as these new combination phone/camera/music devices are it's worth noting that the humble transistor radio is still the most popular communication device ever invented. There are an estimated 7 billion of them floating around the planet and they continue to be made in spite of their seeming irrelevance. But whether you pick an Apple, Android, or something else to plug into your ear it doesn't really matter as long as you can hear the music.