A music download (commonly referred to as a digital download) is the digital transfer of music via the Internet into a device capable of decoding and playing it, such as a personal computer, portable media player, MP3 player or smartphone. This term encompasses both legal downloads and downloads of copyrighted material without permission or legal payment. According to a Nielsen report, downloadable music accounted for 55.9 percent of all music sales in the US in 2012. By the beginning of 2011, Apple's iTunes Store alone made US$1.1 billion of revenue in the first quarter of its fiscal year. Music downloads are typically encoded with modified discrete cosine transform (MDCT) audio data compression, particularly the Advanced Audio Coding (AAC) format used by iTunes as well as the MP3 audio c