Kate Bush is on her way to number one after the chart rules were reset.

The surge in popularity for Kate Bush’s Running Up That Hill is expected to propel her to number one this week.

The hit Netflix series Stranger Things has already propelled the 80s ballad to number two.

Its chances of reaching the top have improved now that the Official Charts have exempted it from a rule that penalizes older songs that are streamed.

Running Up That Hill is currently the most-streamed song in the United Kingdom, with 700,000 plays per day on Spotify.

Those streams would have counted as 3,500 “sales” in previous weeks. This figure will more than double to 7,000 this week.

That’s all because of an obscure but critical rule that governs how charts are calculated in the streaming era.

The Top 40 used to be made up of songs that could be purchased in a record store, and every sale was treated equally. If a record label did not press enough copies of a 7-inch or CD single, it could fall off the chart entirely.

In some cases, record labels even stopped producing a hit single in order to persuade people to buy the album instead (Wet Wet Wet’s Love Is All Around and the Fugees’ Killing Me Softly were both victims of this fate).

However, in the streaming era, every song is always available everywhere. This causes a problem for the charts.