Oasis is back. And this time, the whole world is singing along.

EAST RUTHERFORD, N.J. — So what’s this Oasis reunion really all about? Pomp. Circumstance. Second chances. Picking up where we left off. Nostalgic comfort. Ego maintenance. Fraternal reconciliation, maybe. Cash flow, definitely. A confusingly disproportionate amount of fame generated by four extraordinary songs. Loud thrills with strangers in the dark. Laughter. Belonging. Communion across generations X-Y-Z. Karaoke night for humanity. The re-mystification of rock-and-roll. Subscribe for unlimited access to The Post Save on unmatched reporting. Get your first year for $20

And if you managed to soak up any of these ideas in the high-decibel churn at MetLife Stadium on Sunday night — where the increasingly beloved Brit-pop group was ramping up the American leg of its global reunion tour