If you find yourself humming along to Outlander [1]'s hauntingly beautiful and timeless theme song during the opening credits, you're not the only one. Each season of the show has distinct themes that have been organically reflected in the credit sequence and score; Celtic instruments are played in season one's rendition, while the viola de gamba and French lyrics heard in season two give off the Parisian vibe. In season three, the music completely changes to fit the Caribbean theme after episode nine, "The Doldrums," in which Jamie and Claire begin their journey to the region to find young Ian after he is kidnapped. While the opening montage usually changes to the fit the season and setting, the true essence of the score "The Skye Boat Song" remains the same.

Originally an 18th century old Scottish folk song by Sir Harold Boulton, and later a 19th century poem by Robert Louis Stevenson titled "Sing Me a Song of a Lad That Is Gone," the tune tells the story of Bonnie Prince Charlie's escape from Scotland to the Isle of Skye after the Battle of Culloden. It has been adapted by renowned composer Bear McCreary and sung by Raya Yarbrough to tell the story of Claire's disappearance. Showrunner Ronald D. Moore told Town & Country that they changed the lyrics to fit the show [2] by replacing "lad" in the original song with "lass."

In an interview with Mashable, McCreary explained that in "The Doldrums," he used "Afro-Cuban percussion" as a means of setting the scene [3] for viewers of what's to come for the characters in the rest of the season. However, he reassured them that "the bagpipes and the Scottish and Celtic musical influence is very much rooted in Jamie and Claire. That will always be their sound. They could go to Mars, and I'll still use the penny whistle or the uilleann bagpipes or the fiddle. It's like a blanket for us, we get to wrap up in it." It can be argued that, in a sense, through the transformation of the song each season and the juxtaposition of Scottish undertones with the varying instruments, McCreary is able to convey the transformation of Jamie and Claire's characters as well, who are forced to adapt with their setting. It is dynamic and evolves as the show and characters do, all the while staying true to its roots.

If you want to closely examine the theme song for how it ties into Claire's story, check out the lyrics to the the adapted version of "The Skye Boat Song" below:

Sing me a song of a lass that is gone
Say, could that lass be I?
Merry of soul she sailed on a day
Over the sea to Skye

Billow and breeze, islands and seas
Mountains of rain and sun
All that was good, all that was fair
All that was me is gone

Sing me a song of a lass that is gone
Say, could that lass be I?
Merry of soul she sailed on a day
Over the sea to Skye