Complex sentence: In the 1951 film, Ravenal climbs on board the boat and follows Magnolia to the upper deck to sing the song, and the two walk around the deck while singing the last few lines.
Split into simpler sentences: In the 1951 film, Ravenal climbs on board the boat and then meets Magnolia. He follows her to the upper deck to sing the song, and the two walk around the deck while singing the last few lines.