The rapper/producer announced Friday that he's dishing out free tickets to his mega music event, Something in the Water, for all graduating seniors in the D.C. public school system to celebrate the achievement of getting through high school.

Not just that ... but Pharrell says he's especially inspired by the fact they got through these past couple years with COVID restrictions in place -- and still made it across the finish line.

He says to commemorate the achievement ... he's issuing one free general admission pass per graduating student for SITW next weekend, which is going down right there in town. Pharrell tells the seniors to check with their school teachers/leaders to redeem the gift.

As for how many tickets this might end up amounting to ... it's a bit unclear. Pharrell only said this applies to grads in the public school system -- and according to their website, there are just over 2,000 seniors enrolled this year. No word on how many are graduating.

It would seem the breadth of the giveaway is larger though -- because the Mayor chimed in by saying charter schools are included. It's probably in the low thousands somewhere.