The stage adaptation of a concept album titled "You're a Good Man, Charlie Brown", based on Charlie Brown, Snoopy, Lucy, Linus, Schroeder, and Patty, went into rehearsal in New York City on February 10, 1967. Prior to its opening, the musical had no actual libretto; it was several vignettes with dialog based on the "Peanuts" strips and a musical number for each one. Since Patty was such a weakly defined character in Schulz's strip, she became a composite character in the musical, with much of her material taken from Violet and Frieda in the strip. On March 7, 1967, the musical premiered off-Broadway at Theatre 80 in the East Village, featuring Gary Burghoff as Charlie Brown.