From the new book, The Hidden Secrets & Stories of Disneyland
In June of 1999, Disney Imagineers unveiled the new Tarzan's Treehouse. A reflection of Disney's new movie at the time, Tarzan, it takes guests on a winding and ascending journey through Tarzan's jungle home...an 80' tall tree! Unknown to many, especially those under 20 years of age, is that this attraction replaced one quite similar, the Swiss Family Treehouse. In 1960, Disney released the movie Swiss Family Robinson, a tale about a family shipwrecked on a deserted island, where they built a home from supplies salvaged from their ship and engaged in daily adventures, including battling with pirates. The film was such a success that Disney opened the Swiss Family Treehouse attraction in 1962. Here, as with Tarzan's Treehouse, guests climbed through the tree the Swiss family used as their home.
As with other "new" attractions in Disneyland, Disney Imagineers have paid tribute to the former Swiss Family Treehouse within Tarzan's Treehouse in a number of small ways, the most prominent of which is the playing of the upbeat Swisskapolka song, a tune from the 1960 Swiss Family Robinson movie. If you listen carefully, you can hear it playing faintly on the large old Phonograph located at the base of the tree at the end of the attraction.