Late Nirvana frontman Kurt Cobain would have turned 51 on Feb. 20 — a bittersweet milestone noted by millions of fans, as well as by Cobain's daughter Frances Bean, who marked the occasion by posting previously unpublished photos of her father.

The younger Cobain shared the pictures on Instagram, offering a pair of old family snapshots with the caption "I hope they don’t have the internet wherever you are. I feel like that would be counterproductive. Regardless, Happy Birthday to an angel." The first photo captures Kurt peering at his daughter as she reaches toward an inflatable kiddie pool during what looks like a backyard party; in the second, he's facing the camera with a Breeders T-shirt on and his chin resting in his hand.

Frances' mother and Kurt's widow, Courtney Love, offered her own social media commemoration of Cobain's birthday, also taking to Instagram to post a snapshot — this one of the two of them together in happier times, with the caption "happy birthday baby god I miss you."

Cobain's legacy was also honored by some of his musical contemporaries — including Green Day frontman Billie Joe Armstrong, who wrote, "you're weird, you're an amazing songwriter and you led the charge," and Smashing Pumpkins leader Billy Corgan, who added, "Kurt paved the way, and raised the bar to such incredible heights. His genius should always be celebrated. And he is missed, especially on a day like today ... "