Femi kuti and siblings celebrate fela on his 80th posthumous birthday
I think there may be a small issue here. Fela Kuti, the legendary Nigerian musician and activist, passed away on August 2, 1997, at the age of 58. Therefore, it is not possible for his siblings or anyone else to celebrate his 80th posthumous birthday.
However, it's possible that you may be referring to a celebration or tribute to Fela Kuti's life and legacy, which would be a wonderful way to honor his memory. Fela Kuti's music and message continue to inspire and influence people around the world, and his family, including his children and siblings, have been involved in various projects and initiatives to preserve his legacy.
If you could provide more context or clarify what you mean by "celebrate Fela on his 80th posthumous birthday," I'd be happy to try and help further.