Billboard magazine is changing the way it ranks songs on its Hot 100 singles chart to take into account online music-streaming services like Spotify and Rhapsody, responding to a major shift in how people are consuming music.

“It’s so important that we are vigilant in recognizing a changing marketplace almost constantly these days,” Bill Werde, Billboard’s editorial director, said on Wednesday. “When you look at these streaming subscription services, even in the last year, you really see how they have come of age and I just think the time is now to do this.”

The chart’s methodology has been changed several times since it was established in the late 1950s. In those days hits were determined by counting jukebox plays, spins by radio disc jockeys and sales at record stores. Since the late 1990s the chart has been based mostly on airplay and digital sales.

But streaming services have been growing rapidly in recent years, and have surged even more in the last few months. The number of streams on six of the biggest services rose to 494 million in the week ending March 4, from 300 million a week at the start of the year, according to Nielsen Broadcast Data Systems.