Until 1991, Billboard charts weren’t based on actual unit sales or radio play. Instead, it was assembled using (white) retail clerk estimates of what was selling best and what (white) DJs considered to be “hottest” each week. According to The Atlantic, both groups had reasons to lie. For example, labels would pressure radio stations to favour “hand-picked hits” if they wanted to keep receiving the newest single on time (stations sometimes received bribes to play specific tracks, too). Meanwhile, labels would force inventory on their retailers, who would then overreport sales to convince music fans to buy excess inventory.Naturally, those who ran the music industry saw little need to overhaul how it worked. And thus while the book and film industries had shifted to computerized sales databases in the 1980s, not one of the top six record distributors signed onto SoundScan before its release in June 1991. But this resistance didn’t stop N.W.A.’s N***az4life from debuting #2 on the Billboard Top 100 the very next month under SoundScan. This was the highest charting performance in rap history – and happened without any radio airplay, music video airings on MTV, or a concert tour. The failings of the old honour system were further demonstrated by the fact that N.W.A. debuted at only #21 on Billboard’s R&B chart, which wasn’t yet on SoundScan. Somehow it was possible that N***az4life was the second biggest album in the country by units purchased, but 21st in its own genre when it came to what was “selling” and “hottest.” One week after it’s release, the album hit #1 on the Billboard chart (displacing R.E.M) as hundreds of thousands flocked to the record store in search of the “surprise” hit.In the following years, the R&B/hip hop genre achieved three other industry “firsts." It saw the fastest rise from a non-top ten genre to Billboard’s most popular one, has been the most dominant #1 by share, and holds the longest run as #1 (note the chart below ends in 2010, but this reign persists through to date).