Mooney joined his first teen pop group in Larne, Northern Ireland in 1974, called Flame, who toured with the chart acts of the time, but released no recordings.
In 1975, Mooney moved to Manchester where he formed the progressive rock band Accidents with keyboardist Paul McKavanagh and drummer Alan Arenstein.
[2] Although it did not chart, the track attained cult status being re-released on the White Dopes on Punk CD in 2005, and again on vinyl on the German Still Unbeatable label in 2009.
During the 80s, Mooney was lead vocalist and bassist with Park Avenue, who toured with chart acts and released their only single "Raffy and Sean/No Control" on the independent label Q Records, which reached the lower end of the UK Top 100 in 1983.
Mooney also appeared on a sporadic basis as bassist and vocalist with 70s Glam rock act The Glitter Band during this period, also recording new versions of their hits "Angel Face" and "Didn't Know I Loved You" with original member John Rossall.
In 2001 Mooney worked with UK comedian Peter Kay as a session singer and bassist on the successful Phoenix Nights TV series, notably singing "Don't Cry Out Loud".
In December 2007, whilst still with The Dakotas, Mooney was asked to stand in as lead vocalist and bassist with 60s and 70s British chart band The Fortunes due to the illness of original frontman Rod Allen.
The band released a series of digital and vinyl singles, "Dennis Votes" (2019 and 2021), "Down The Drain" (2020 and 2021), "Lockdown Baby" (2020),[3] "Telephones" (2021), "(How Does It Feel to Be) Great!!!"