Details: Dog & Butterfly is the fourth studio album by American rock band Heart, originally released on October 7, 1978 through Portrait Records. As Heart themselves noted on the album's release, side 1 was the "Dog" side, and was the more "rocking" compared to the "Butterfly" side 2, which was all ballads, with the exception of the closer "Mistral Wind", which, in many ways, epitomized the trademark sound for which Heart would be remembered: folksy ballads shifting into searing hard rock explosions.