These are some of the best attempts at TikTok's 'Crazy' riff challenge

The 'Crazy' riff challenge is taking over TikTok right now with users showcasing their singing skills to the tune of Gnarls Barkley's 2006 hit.

In the challenge, music buffs sing the line "I remember when, I remember I remember when I lost my mind" while riffing and showing off their vocal range.

Experienced pros such as JoJo and James Arthur have been trying their hand at it (and impressing us), and there's even been some unexpected underdogs.

Of course, there's been some fails too...but even they make for great entertainment.

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