One single Wu-Tang Clan album has sold for millions. The legendary hip-hop group's secret one-of-a-kind album is called "Once Upon A Time in Shaolin" and was sold to a private American collector for "millions," according to Music Times. Because the album is such a limited edition item, there will not be another reproduced commercially for 88 years.

The sale was completed on the online auction site Paddle8 back in May but it has taken this long to get all the paperwork figured out, according to Forbes. The album, which is a double-album, was produced by Tarik "Cilvaringz" Azzougarh with RZA and was recorded with the rest of the crew over a period of six years.

It's a very unusual approach to releasing an album as only one copy was made but their ultimate goal is to return the value of music, which has significantly lowered ever since streaming and downloading became available.

Part of the deal, though, is that whoever the anonymous buyer must wait the 88 years to release any of the contents of the album to the public, according to TMZ.

"For art to change the way people think, it has to come from an extreme place," said group member RZA back in March, according to Forbes. "No monumental change ever started with a compromise or a small shift. It starts extreme."