The research company found in its mid-year report that for the first time in Nielsen Music history, R&B/hip-hop has taken the largest share of volume, which measures album and track sales and audio and video streams.
R&B/hip-hop took 25.1 percent of volume, knocking out rock, which had always taken the largest share in the past.
Rock slipped to second at 23 percent of the total volume, though it did still have over 40 percent of albums.
R&B/hip-hop, however, dominated streams — 30 percent of streams came from the genre, whereas rock only took 18 percent.
Country still lags in streams, taking only a 5.6 percent share of volume. But physical albums and digital album purchases still remain strong at 14 percent and 12 percent of volume, respectively.
Out of the R&B and hip-hop genres, Kendrick Lamar and Drake stood out in particular.