US President Barack Obama has praised the work of Frankie Knuckles.

The 59-year-old, who was a pioneer of house music, passed away in late March.

Obama and his wife Michelle sent a letter dated April 17 to friends and family of Knuckles before his memorial service took place on Monday (April 21).

The house man's friend DJ David Morales uploaded a scan of the letter to his Facebook, with the Obamas saying that Knuckles was a "trainblazer" who "captured our attention and ignited our imaginations".

They added: "We were deeply saddened to learn of Frankie's passing, and we extend our heartfelt sympathies as you mourn his loss and reflect upon his life.

"He was a trailblazer in his field, and his legacy lives on in the city of Chicago and on dance floors across the globe."