sentences:  None of the actors sang background; they lip-synched to recorded singing by the Ron Hicklin Singers, composed of brothers John and Tom Bahler, Jackie Ward (who as Robin Ward had a #14 hit "Wonderful Summer" on Dot Records in 1963 ), and Ron Hicklin.Cassidy was originally to lip sync to dubbed vocals with the rest of the cast, but convinced Farrell that he could sing and was allowed to join the studio ensemble as the lead singer.He and Jones were the only two of the show's actors who sang on the recordings.