Shefrin passed away in his sleep on 6 April (11) in Encinitas, California after a long battle with Parkinson's disease.
Throughout his showbusiness career, which spanned more than 40 years, Shefrin represented stars including Guy Lombardo, Dick Clark and Don Rickles, while he also organised the Beatles' first New York appearance at Carnegie Hall in 1964.
He also helped launch the writing career of moviemaker Woody Allen in the 1950s by hiring him as a school student to write witty comments to be sent to gossip columnists and attributed to Shefrin's clients. Allen remembered his former mentor more than 40 years later by handing Shefrin a small part in his 1994 film Bullets Over Broadway.
Shefrin is survived by his wife, Sophie, and son, Paul.
The actress has signed on to play Sister Jamison Connelly, a nun whose faith is tested when she agrees to sponsor a 19-year-old drug addict, in High.
The play, written by Matthew Lombardo, will be directed by Rob Ruggiero.
Turner's last Broadway appearance was her 2005 Tony-nominated role in the revival of Who's Afraid of Virginia Woolf?
High opens on 19 April (11) at New York City's Booth Theatre.
Her nod has come less than a month after the show closed in New York and Harper admits its a huge acknowledgement for the cast, director Rob Ruggiero and playwright Matthew Lombardo.
She tells WENN, "I can't say vindication but it's very, very sweet. I can't say bittersweet because we closed on April 11th, so I've had three weeks or so to sob and be upset... It kind of has solidified us in Broadway history even though the show closed early."
And Harper, who is now touring with the production, insists the show failed because an investor dropped out at the last minute.
She adds, "He dropped out to the tune of an excess of $500,000, so everybody else was trying to put in money. My husband contributed substantially and other investors stepped up, but I don't think we had enough publicity and enough advertising.
"The truth is you have to clear at least $800,000 a week. We were underfunded."
But the actress' Tony Awards nomination has given the play a new life as it tours America: "I'm gonna keep playing it in other cities. It's not over yet by any means."