Predicting Chart Toppers Before They Make the ClimbNext Big Sound's data predicts music's breakout stars.

Earlier this year, rap sensation Iggy Azalea became the first artist since the Beatles to secure the No. 1 and No. 2 spots on the Billboard Hot 100 simultaneously with her first two charting singles. That was no surprise to Next Big Sound, which had Azalea on its end-of-2013 list of artists most likely to hit the Billboard Hot 100 in 2014.

In collecting data from more than 15 social media sources, Next Big Sound has given the slumping music industry a vital new tool to understand how "these social signals relate to the underlying business," says Alex White, who founded New York-based Next Big Sound with his Northwestern University classmates Samir Rayani and David Hoffman.