The late producer Aaron Spelling had two distinct and equally popular formulas in the 70's & 80's. On one side, you had the crime dramas (i.e. The Rookies, Charlie's Angels), which, despite each being different, had cookie cutter plots that seemed to be recycled over and over again. On the other, there were the ensemble anthologies. In the 80's, there was Hotel, but before that, Spelling used ABC's Movie of the Week to develop his first two anthology series, Fantasy Island & The Love Boat.
It took three TV-movies, produced between 1976-7, before Love Boat became a weekly series, and it took almost as long, before the core cast came together.
For example, Gavin McLeod wasn't the original Captain, having missed the first two movies due to commitments to The Mary Tyler Moore Show. Future Congressman Fred Grandy wasn't in the first movie, either, presumably due to being on the children's series, The Monster Squad. However, there was a veteran presence, thanks largely to well-traveled veteran Bernie Kopell, whose resume includes Get Smart, That Girl, & When Things Were Rotten. Ted Lange had one previous series, the short-lived That's My Mama, before becoming an icon as bartender Isaac Washington.
As it ended up, Love Boat (which dropped the The in the final season), lasted nearly a decade, and became a destination point for viewers, coupled with Fantasy Island for most of the run, on Saturday nights. In fact, one plot thread crossed between the two shows one night, involving guest star Loni Anderson. Crooner Jack Jones recorded the familiar theme song, but was replaced by Dionne Warwick in the final season. Frequent guest Charo even recorded her own version sometime in the 80's.
After a healthy rerun cycle on cable, the series returned in the 90's with a new cast, including one of Spelling's favorite actors, Robert Urich, but the revival, sub-titled The Next Wave, failed to get past one season on UPN.
Chuckcollins uploaded a sample open, with the theme sung by Jack Jones.
The theme was composed by Paul Williams, who for some reason didn't get the credit he deserved. Go figure.