The number of acts was experimented with during previews.
You may get the impression from reading Craig Zadan's Sondheim & Co. and Meryle Secrest's Stephen Sondheim: A Life that Henry Lascoe died while Anyone Can Whistle was out of town, but he recovered well enough from the medical problems he had during the pre-Broadway run of the show to go to California and do some television work. His death did not occur till Sept. 1, 1964, months after he was in Anyone Can Whistle.
The Broadway opening was originally scheduled for March 26, 1964, but a week after the tryout opened in Philadelphia, it was announced that the opening would be delayed till April 1. Then after Henry Lascoe had to leave the cast because he'd had a heart attack and he was replaced by Gabriel Dell, the opening was delayed again, this time to April 4, in order to give Dell more rehearsal time (or so press reports stated).
