Trespass, by Genesis (1970): If you'd been one of the few people to buy Genesis's debut album in 1969, their follow-up would have been a pleasant surprise. From Genesis to Revelation is a fun listen with full hindsight engaged, but it didn't offer much of a hint of where the band would go in the next five years. On Trespass the band broke out of the 3-minute pop song format and started exploring the more elaborate arrangements that would characterize their golden years. It's not all completely satisfying, but the high points would have given a 1970 fan hope for the future. While it's mostly more acoustic and pastoral that would become typical, dynamic closer "The Knife" hints and the more aggressive tone that Steve Hackett and Phil Collins would bring to the band on the next album.