Kendrick Lamar’s surprise Untitled Unmastered album debuts at No. 1 on the Billboard 200 chart, earning 178,000 equivalent album units in the week ending March 10, according to Nielsen Music. Of that sum, 142,000 were in pure album sales.

The set was released without advance notice on March 4 and gives Lamar his second chart-topping set in less than a year, following To Pimp a Butterfly. The latter (his first No. 1) was released on March 16, 2015, and bowed atop the listwith 363,000 equivalent album units in its first week, of which 324,000 were in pure album sales.

The Billboard 200 chart ranks the most popular albums of the week in the U.S. based on multi-metric consumption, which includes traditional album sales, track equivalent albums (TEA) and streaming equivalent albums (SEA). The new March 26-dated chart (where Lamar is No. 1) will be posted in full to Billboard’s websites on Tuesday, March 15.

Lamar is the third act since January 2015 to notch two No. 1s in less than 12 months time, following Drake and Future.

Lamar tweeted that Untitled Unmastered consists of “demos from To Pimp a Butterfly. In raw form.” Like the album’s title, its tracks are named unconventionally: “untitled 01 | 08.19.2014.,” “untitled 02 | 06.23.2014.” and so on.

Untitled Unmastered was released to digital retailers and streaming services on March 4 through Top Dawg/Aftermath/Interscope Records. (Streaming equivalent units comprise 16 percent of the new album’s total first-week units.)

A physical CD release of Untitled’s explicit edition followed on March 11, while an edited version is due out March 18.

billboard.com