In most cases, once the frontman leaves a popular band, it's curtains for that act. The character of a singer's voice is extremely difficult to replicate or improve upon, and let's not even get into the complexities of songwriting. However, these 10 vocalists stepped up to the challenge and achieved unbelievable feats.

In this list, there are two types of replacement singers present. One type took over when a group was still in relative obscurity, launching the project to new heights after something intangible just clicked. Philip Anselmo replacing Terry Glaze in Pantera and Corey Taylor replacing Anders Colsefni in Slipknot both fall into this category and their contributions simply can't be underestimated.

The second, and perhaps most difficult, type took over for established legends and rock gods only to achieve that status themselves. You'll find the usual suspects such as Iron Maiden's Bruce Dickinson and AC/DC's Brian Johnson on this list, but some of the men featured are sure to surprise you. Two different vocalists who sang for one single iconic act even grabbed Top 10 spots.

Check out the video above for the 10 Best Rock + Metal Replacement Singers!

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