Red Rock Trivia 07/20

Question: This day in 1968 this band’s second album entered the US charts for the first time. The album contained the 17-minute title track that filled the second side of the LP which went on to sell over 4 million copies in the US alone. What’s the name of the band and album?

Answer: Iron Butterfly’s second album, ‘In-A-Gadda-Da-Vida’