In what the music biz sees as a long overdue move, Nielsen SoundScan and its client Billboard will soon implement radical changes in the way album sales are calculated for the weekly chart that remains a key metric of an artist’s popularity. Beginning with the album chart that will be published Dec. 3 (covering sales for the week ending Nov. 30, which climaxes with retail’s Black Friday), music streams from services like Spotify and Beats Music will be tabulated as part of the data employed to rank the nation’s most popular albums. SoundScan will equate 1,500 song streams as the...