There have been many times over the years when you probably thought a riff or a groove in one song sounded like something else you knew. And it's that simple idea that began the mash-up craze. In recent years, seemingly every wannabe production geek with Pro-Tools or GarageBand has attempted to create oddball pairings of songs that somehow match perfectly, but not every mash-up is a gem.

However, there have been some mash-ups along the way that are just brilliant, with their ability to pair two seemingly divergent artists together into something unique and utterly listenable, often breathing new life into overplayed songs in the process. With that in mind, Loudwire is teaming with Ultimate Classic Rock and to bring you 15 Mash-Ups You Need to Hear. Click the red button below to begin the mind-blowing mash-up experience.

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