Leclercq started composing music at the age of 11, and adopted a nu-disco style under the name "Madeon" in 2010. In the fall of that year, at the age of just 16, he gained popularity for his award-winning remix of The Island by Pendulum which was praised by the likes of Skrillex and Pendulum front-man Rob Swire.
In 2011, he created a remix for Yelle`s "Que veux-tu," and then went on to remix deadmau5`s Raise Your Weapon which was praised by deadmau5 himself on Facebook and other social utilities. In the summer of 2011, a YouTube video of his live mashup "Pop Culture" went viral, which combines 39 pop hits into one song. As of November 2012, it has approximately fifteen million hits.