The first generation iPod hit a milestone over the weekend, marking its 15 year anniversary. What once was just a concept became a classic; the iPod debuted on October 23, 2001 to forever change the way we listen to music.

As The Verge reports, the original iPod sported a 5GB hard drive that held over 1000 songs in, a built in FireWire port for fast and easy computer syncing, and a rotating scroll wheel for browsing through your music files. The revolutionary iPod had an immediate impact on the portable music business, with its new practical and convenient way to store and listen to music. The younger generation of this new digital era will never know the struggle of toting around CD and MiniDisc players with a large collection of physical discs. Before iPods hit the scene, Sony MiniDisc mp3 players were a popular way to have digital music in your pocket, a great alternative to carrying around clunky CD players. While the MiniDisc player still required the use of optical media to achieve high quality digital mp3 sound, it had a more compact form factor and users began gravitating to these devices in 1992.

iPodCdMiniDisc The Apple iPod led to the demise of the need for optical media. Emma Farrer / Getty Images

Fast forward to October of 2001 and the iPod burst onto the scene offering music lovers everything they loved about their MiniDisc players, without the need for optical media to transfer digital songs to their device. Apple’s second generation iPod was released in July of 2002, offering a storage capacity that held up to 4,000 songs. At the time, the iPod had sold 600,000 devices since its debut. Apple was on a roll and in April of 2003, launched the iTunes Music Store which had a library of 200,000 songs selling at 99 cents a pop. Its thinner and lighter third generation iPod was released at the same time and stored 7,500 songs, iTunes sold a million songs in its first week. By June of 2003, the iPod itself reached one million sales. Following the success of the iPod, Apple released smaller versions of the device including the iPod mini and the iPod shuffle before introducing the iPhone in 2007. The iPod started it all.

Over the weekend, nostalgic music lovers reminisced about a revolutionary portable gadget first introduced by Apple founder, the late Steve Jobs. As the iPod became more popular over the years, it eventually put an end to optical media forcing Sony to finally stop producing MiniDisc portable audio players in 2013.