2011 collection. The world's best-selling, multi-artist album series, NOW That's What I Call Music!, is celebrating unparalleled success and a milestone release with its 40th numbered volume. NOW That's What I Call Music! Vol. 40 features 16 current major chart hits from today's hottest artists, including Britney Spears, Rihanna, Foster The People, David Guetta featuring Usher, and more, plus four up-and-coming NOW What's Next New Music Preview tracks.