Der Album Track "Toop Toop" wurde schon von Madonna und David Guetta gesamplet, auf "Eye Water" ist Pharrell Williams am Mic als Gast! What if we took you back to your untroubled teenage days, when all seemed complicated and easy to reach at the same time? That is exactly what Cassius managed to transpose in 15 Again: a carefree music, coloured by some deep songs; like an emancipated soul, but always tormented. The hit "Toop Toop", sampled by Madonna or David Guetta, among others, and the intense "La Notte" illustrate perfectly this state of mind of the youth. Pharrell Williams is present on the song "Eye Water".