I don't know if he is advanced or not, but Leon Redbone certainly deserves a mention. I came across this today, and here are some of the highlights:
"Most dedication on the part of a traveling musician is involved with staying aware of time and space." -- Leon Redbone
His early career gained momentum when Bob Dylan, in a Rolling Stone interview, mentioned that if he were ever to start a label, Redbone would be the first artist he wanted to record.
Ever the character and personality, Redbone has popularized elements of our pop culture, including advertising jingles like Anheuser Busch's "This Bud's For You."
He's acted in the offbeat feature film "Candy Mountain," provided the television theme songs to "Mr. Belvedere" and "Harry and The Hendersons" and had a memorable guest role as a quixotic, guitar-wielding guardian to the character Corky on ABC's critically acclaimed series "Life Goes On."
More recently, New York choreographer Eliot Feld performed "Paper Tiger," a ballet around 11 of Redbone's signature songs. And Redbone was the voice of a snowman in the movie "Elf."
The last time Redbone he was in the area, he recalls, an audience member brought him a sack of fresh farm cherries.He remembers how delicious they were and keeping in mind that the best ones are firm, he encourages anyone who is like minded to bring him another sack of those wonderful California cherries.
About stage performance, Redbone says,"There are two methods, one is to run out on stage and basically let loose and communicate with the audience on a personal level. The other one is to completely ignore the entire situation and try to concentrate on what it is you are doing and at the same time, not dwell on it, disconnect from your physical surroundings, which is contrary to performing. So I don't know if performing is necessarily a good definition for what I do.It may be closer to a sance [sic] than anything else."
As I have said in the past, the Advanced Theory is mysterious even to me, so some artists will seem advanced even though they don't meet the usual criteria. I think Leon Redbone probably falls into the new category "advanced overt," but I can't prove it.