This is a popular musical motif found throughout the scores of adventure movies and TV shows.
The classical stereotype of the Irish Immigrant throughout the colonial era (and by extension, the Irish farmer) is an earthily honest man who is one with the world around him, simultaneously able to accept the hardships of life and take any hardship life throws at him, resulting in a robust, innocent and pure optimism that anything is possible through joyful, honest hard work.
Therefore, if a composer wishes to evoke that spirit of optimistic idealistic wonder (especially through montage of True Companions working together for a common cause), the joyfully whimsical strains of the Irish fiddle are invoked to stir similar emotions in the audience.
Note that this musical motif does not always have to apply to settings in Ireland or even have any Irish characters; regardless of the presence or absence of Irishmen in the story, it will subconsciously take the audience on an emotional level back to the classical romanticism of the colonial pioneer era, where there is still an unknown adventure in every horizon, ready for your bravery and optimism to challenge.
Obviously, a popular staple of the Hard-Work Montage.
- The Hard-Work Montage sequences and "exploration" sequences for the anime Bodacious Space Pirates deliberately uses this trope to take you back to the Golden Age of Piracy, albeit in a futuristic space setting.
- Used in Earth Maiden Arjuna during Juna and Tokio's Hard-Work Montage at the mountain man's home.
- My-Otome uses more playful variations on this to invoke the optimistic adventurousness of our Country Mouse heroine, Arika Yumemiya.
- Practically the entire musical score of the Heroic Fantasy anime Fairy Tail is made of this trope;
- Spice and Wolf emphasizes the hard-working and industrious nature of our travelling merchant heroes by occasionally using this in its soundtrack.
- Laid-Back Camp utilizes the fiddle in its incidental pieces to capture the sense of adventure and majesty the girls encounter while camping in the outdoors.
- Someday's Dreamers uses these to invoke the innocent wonder of a young magician trying to find her place in the world.
- CLANNAD frequently has this as a nod to the Irish connections of its namesake, as well as to invoke a sense of whimsical romanticism and everyday wonder.
- Seitokai Yakuindomo has at least one song in it's soundtrack like this, often used during athletic events.
- The Lord of the Rings does this with music thematically linked to Rohan. Variations of this main "Rohan theme" pop up throughout The Two Towers and The Return of the King whenever the people of Rohan are doing much of anything noteworthy or dramatic.
- The score of the late James Horner for the James Cameron film Titanic (1997) celebrates the resilience and optimism of the Irish spirit with liberal and frequent use of this trope. It becomes especially heartwarming when you remember that Horner was himself Irish, and the RMS Titanic was an Irish ship. Having been built in Belfast, like its sister ships the Olympic and Britannic, many of the ship's crew and third class passengers were from that community, and the sinking hit them hard.
- The Boondock Saints main theme "Blood of Cuchulainn" fits the two working-class Irish protagonists like a glove.
- Far and Away, scored by John Williams, underscores The Determinator spirit of the Irish-battlers played by Tom Cruise and Nicole Kidman with this trope.
- Similarly, the musical score for Master and Commander (starring Russell Crowe) loves using this in its more optimistic sequences, though justified as it is set in the Napoleonic Wars. Somewhat inevitable as lead characters Jack Aubrey and Stephen Maturin are, respectively, a violinist and an Irishman.
- Braveheart is in love with this trope; its a wonderful example of its flexibility. For although the heroes are Scots (plus an Irishman), the passionate strains of said trope still do much to evoke the energetically violent and rapacious spirits of many Irish and Highlander-Scots sub-cultures.
- Sherlock Holmes (2009) features Irish violins in some scenes. There's also "The Rocky Road to Dublin" during Holmes' boxing match by the veteran Irish ensemble The Dubliners, though this one has a banjo and an Irish flute instead.
- Sherlock Holmes: A Game of Shadows has some as well, as well as some more "Gypsy" takes on the instrument
- Used in the second episode of Better Call Saul to accompany a montage of Jimmy McGill doing mundane work as a public defender.
- The Dropkick Murphys' iconic hit "I'm Shipping Up To Boston", about a sailor who's going back to Boston to find his missing wooden leg, has a violin prominently featured. The Dropkick Murphys are an Irish-American "Celtic punk" band from Massachusetts. The song is prominently featured in The Departed in a scene where the Irish-American Boston cops are going off on their own adventure (namely, a big raid).
- This is invoked in the heartwarming musical score of Atelier Totori: The Adventurer of Arland to accentuate Totori's youthfully enthusiastic idealism.
- The most notable part of the classic Halo theme behind the Gregorian chanting is the prominent adventurous string section. Admittedly though, it lost some of its jauntiness after the first game.
- The The Legend of Zelda: The Wind Waker intro theme features a nice violin melody later into the song, fitting a story about sailing away to adventure.
- The same melody shows up again during the second half of the game, played on a blue fiddle, and it turns out to be some appropriate Magic Music, which reconnects the current Wind Sage (in this case, Makar the Korok) with his mystic ancestry. When the sage plays his fiddle at the temple's gates, the temple is unlocked.