Glen Campbell's longtime songwriting partner and friend, Jimmy Webb, used Facebook to eulogize the country legend after his passing on Tuesday (Aug. 8). Webb's heartfelt words commemorate his friend and mentor with great emotion.

"Let the world note that a great American influence on pop music, the American Beatle, the secret link between so many artists and records that we can only marvel, has passed and cannot be replaced -- my friend and brother in music, Glen Campbell," Webb writes at the beginning of a beautiful tribute. Webb began working with Campbell as a young songwriter, when the legendary performer recorded his song "By the Time I Get to Phoenix. The two went on to record more than 100 songs together over the years.

"One of his favorite songs was “Try a Little Kindness,” in which he sings 'Shine your light on everyone you see.' My God. Did he do that or what?," Webb continues. "Just thinking back, I believe suddenly that the 'raison d’etre' for every Glen Campbell show was to bring every suffering soul within the sound of his voice up a peg or two. Leave ’em laughin'. Leave them feeling just a little tad better about themselves; even though he might have to make them cry a couple of times to get ’em there."

Webb said in 2102 that Campbell's "long goodbye" -- his life with Alzheimer's disease, which Campbell revealed he had in 2011 -- was one of the most painful things he has ever been through.

"When it came to friendship, Glen was the real deal. He spoke my name from ten thousand stages. He was my big brother, my protector, my co-culprit, my John crying in the wilderness," Webb says in his Facebook post. "I am full of grief ... I am too upset to write very well or at any great length. It’s like waking up in the morning in some Kafka-esque novella and finding that half of you is missing."

Often accompanying Campbell on the piano, Webb was a fixture in Campbell's musical career for decades. He says that Campbell's legacy will not die with the artist.

"This I can promise: While I can play a piano, he will never be forgotten," Webb concludes. "And after that, someone else will revel in his vast library of recordings and pass them on to how many future generations? Possibly to all of them."

Country Artists Pay Tribute to Glen Campbell