与Black Sabbath反其道而行之，从而构筑了重金属另一高峰。

在深紫的精选集上有段这样的评论：There were three bands,Led Zeppelin,Black Sabbath and of course,Deep Purple.Those three bands were the coolset(or uncoolest,depending on the decade you were listening to them)for you,your older brother,or maybe even your father to name drop.All three have a suitably colourful history worthy of investigation.
在黑色安息日的精选集上有段这样的评论：In the wake of the british blues boom in the sixties some new,heavy bands had emerged from the dying scene.Fleetwood Mac...,and the Yardbirds...,Keith Moon....Even future hard rock titans Deep Purple were still a cabaret act and about to record a concerto....
1969年5月31日开始，Purple MK1和 Episode Six合并，成立了Deep Purple MK2，全新阵容认真分析研判了当时时势，包括刚发行的黑色安息日的Black sabbath,发现市场当时的欠缺，于是1969-1970年录制发行了Deep Purple In RocK。这张专辑标志着Deep Purple MK2江湖地位的正式确立。
对比黑色安息日的Black sabbath和Deep Purple In RocK这两张专辑，你会发现风格同归而殊途，风格一慢一快，一阴暗一绚烂，主唱声音一阴沉一高亢，你是男巫satan，我就是速度之王。
这张碟是重金属的另一座高峰，里面跳跃着无穷无尽的灵感和生命力，值得一听再听。
因此必须维持力荐级别。