Premise: Led Zeppelin . Although the group was initially unpopular with critics , they achieved significant commercial success with albums such as Led Zeppelin ( 1969 ) , Led Zeppelin II ( 1969 ) , Led Zeppelin III ( 1970 ) , Led Zeppelin IV ( 1971 ) , Houses of the Holy ( 1973 ) , and Physical Graffiti ( 1975 ) . Physical Graffiti is the sixth studio album by the English rock band Led Zeppelin , released as a double album on 24 February 1975 by their newly founded imprint label Swan Song Records .
Hypothesis: Led Zeppelin put out the album Physical Graffiti in the 20th century.
Label: ENTAILMENT