Grateful Dead drummer Mickey Hart is mourning the loss of his "little brother" Bob Weir

In a post on Instagram, Hart wrote: " Bob Weir was a little brother to me for almost sixty years. He was my first friend in the Grateful Dead.

"We lived together, played together, and made music together that ended up changing the world."

He added of the musician: "Bob had the ability to play unique chords that few others could. Long fingers, that's the difference. Jerry [Grateful Dead frontman Jerry Garcia] once told me that the harmonics Bob created became an inspiration for his own solos.

"When all of us were entrained, rhythm section, guitars, and voices ... it was transcendent. What was a lifetime of adventure boils down to something simple- we were family and true to the music through it all."

He shared a number of pictures from his time in the Grateful Dead and added: "These photos show the bookends of our lives together. Still cannot believe he's gone. I miss you so much already, dear friend."

Weir's death was announced in a statement posted on his own Instagram page, which read: "It is with profound sadness that we share the passing of Bobby Weir.

"He transitioned peacefully, surrounded by loved ones, after courageously beating cancer as only Bobby could. Unfortunately, he succumbed to underlying lung issues."

The statement went on to share details of his extraordinary career and how he managed to continue working despite undergoing cancer treatment last year.

The message explained: "Bobby's final months reflected the same spirit that defined his life. Diagnosed in July, he began treatment only weeks before returning to his hometown stage for a three-night celebration of 60 years of music at Golden Gate Park.

"Those performances, emotional, soulful, and full of light, were not farewells, but gifts. Another act of resilience. An artist choosing, even then, to keep going by his own design ...

"There is no final curtain here, not really. Only the sense of someone setting off again. He often spoke of a three-hundred-year legacy, determined to ensure the songbook would endure long after him.

"May that dream live on through future generations of Dead Heads. And so we send him off the way he sent so many of us on our way: with a farewell that isn't an ending, but a blessing. A reward for a life worth livin'."