Before Beats: A Walk Through Apple's Digital Music History, 1977 to 2014

Apple introduced its first version of iTunes, built after its acquisition of early MP3 player SoundJam MP in 2001. Two years later, with iPod hardware and iTunes as a software framework, Apple could finally introduce its biggest game changer yet: a digital storefront stocked with 99 cent songs that upended the music industry as we knew it.

Source: Wikimedia Commons