As f(x) enjoys the success of their comeback single "Red Light," the original demo has also emerged online.

The original demo of "Red Light" is written and performed by the artists under Phrased Differently, a British music publishing, production and artist development company. Their company of writers has created songs made famous by K-pop groups like EXO and Shinee.

After listening to the original, English demo of "Red Light," some f(x) fans have expressed a preference to the demo over the final product.

"The original demo is way better," commented Adrienn Horvath on YouTube. "SM Entertainment should have released that."

"This is like a million times better than f(x)," wrote Kat Blaque on July 8.

"I think SM rearranged it so it could have its own feeling when f(x) recorded it," added Stephen Harris Jr. "Plus, if you listen to this version based on vocals, Only Krystal, Sulli and Luna would've been able to pull it off. Maybe Victoria, but Amber wouldn't have had a portion. They both sound good because the arrangement is different so they both have a different feeling."

On July 2, f(x) uploaded the music video for their comeback single "Red Light" on YouTube. So far, it has accrued nearly 6 million views on YouTube.

However, some comments regarding the visuals have been less than complimentary. In one of the early scenes in the music video, f(x) member Krystal can be seen holding a large burning book, and some observers have accused the group of Bible burning because of it.

Despite such controversy, upon its release, the eponymous album accompanying "Red Light" reached the top of all nine major music charts in Korea, including Melon, Mnet, Genie, Monkey3, and Naver Music.

Listen to "Red Light" and its original demo below.