His debut album Evening Train resulted from his time spent studying music and management at Coláiste Stiofáin Naofa in Cork.

It featured tracks which had previously won Flannery two categories at the International Songwriting Competition in Nashville, Tennessee.

[5]Flannery cites an encounter with the music of Kurt Cobain and Nirvana as a direct influence on his desire to become a musician.

[7] However, he is keen to express his fondness for stonemasonry and its position alongside his music: "I wasn't going to sit in a room and write songs seven days a week and live on bread and beans.

[2] Before its release Flannery and a friend who worked alongside him in the stonemasonry business embarked on a three-month trip to the United States, living in Williamsburg, Brooklyn.

[2] Reviewers noted its "astute and sophisticated lyrics", its "strong, imaginative melodies", its Tom Waits sound.

[3][9][11] The RTÉ Guide later said, "His voice was like Tom Waits meets the howling of a grizzled freight train hobo".

[12] entertainment.ie reviewer Lauren Murphy described it as "an album dripping with maturity, poise and potential" and that "the most astounding thing" was his age of 21 years.

[13] In June 2019, as part of the Cork Midsummer Festival, The Everyman and Rosa Productions presented the world premiere of Evening Train, a new musical inspired by Mick Flannery's acclaimed concept album of the same name.

[14] Flannery’s album, written from different character perspectives, suggests the main figures: two divided brothers, Frank and Luther, and a spirited, forlorn young woman, Grace, all dreaming of some form of escape from dusty realities and unpromising futures in a small town of gamblers and strivers.

Playwright Rani Sarma developed this theme into a love triangle saddled with questions of debt and fate, where parents are either haunting absences or demanding presences, and a younger generation stews in fragile promises and ruinous addiction.

[15] Gambling being a focus of the musical, the game of bluffs and tells, requires working out characters within a strict economy of expression.

[11] RTÉ reviewer Harry Guerin commented: "If you're adamant that Ireland may sink with another singer-songwriter on tour, then this is a record to seek out; you won't notice the time passing and the nation will remain afloat".

[7] He performed a duet of "Christmas Past" with Lisa Hannigan in December 2008 after Today FM's Tony Fenton paired them together for a radio show broadcast from a rooftop.

[22] "Tomorrow's Paper" was translated into the Irish language for a CD titled Ceol '09, an annual compilation released by Seachtain na Gaeilge.

[23] Flannery performed a cover version of "The River" on The Ray D'Arcy Show's Discover Ireland Feel Good Tour stopover in Carlingford and Cooley Peninsula in March 2009.

[24] A deluxe edition of White Lies, which featured a duet of the song "Christmas Past" with Kate Walsh, was released in 2009.

[20][27][28][29] Flannery said being asked to perform there was "daunting [...] In many ways I have drifted into this career and still have to pinch myself regularly to make sure I am not imagining it all".

[32][33][34] On 31 December 2009, he performed a date at the Cork Opera House as part of celebrations marking the end of the decade.

It spent three weeks at number one in the Irish Albums Chart and singles "Gone Forever" and "No Way To Live" enjoyed a lot of airplay.

[40] Game of Thrones' Aidan Gillen starred in the music video of Mick Flannery's song Cameo.

Mick touches on loose themes of ambition and the search for a meaningful life in the context of a musician’s sometimes feckless and dysfunctional lifestyle.

In May 2020, Mick Flannery teamed up with New York-based director Samantha Scaffidi to collaborate on Run a Mile, a new song and video to raise funds Women’s Aid, a national frontline organisation helping victims of domestic abuse.

[50] By re-contextualising Scaffidi's short film 'BOUND' accompanied by Flannery's song, they made effort to raise awareness of domestic abuse during the COVID-19 lockdown.

[54] Capturing the magic combination of raw talent, nervous energy, and deadpan, self-deprecating humour that makes his gigs so special, the album serves not only as a celebration of the joy of live music, as well as support in the fallout of lockdown.

In The Game received numerous accolades from the press on both sides of the pond with American Songwriter calling it, 'A sorrowful Masterpiece', Irish Times proclaiming, 'Two Stars are Reborn', and UK Publication The Line of Best Fit saying, 'Every song on in the Game takes you on a journey, each player has their moment, each instrument sharing the weight of the record’s gloriously heavy sentiment'.

The pair toured the record in the U.S. directly after it was released sharing dates with Kathleen Edwards, appearing at the Americana Festival in Nashville, and were also invited to open for Phoebe Bridgers at her Philadelphia show at the Mann Center.

The Irish Times placed him at number forty-six in a list of "The 50 Best Irish Acts Right Now" published in April 2009,[66] commenting on his album White Lies: "With this stunning exhibition of the gravel-voiced musician's abilities, Flannery turned his hand to mournful piano ballads and catchy guitar tunes with a flair that far surpasses his 25 years".