Originally from Marino, Dublin, but calling Sligo home,[1][failed verification] Wickham was a founding member of In Tua Nua (left in 1985 replaced by Aingeala de Burca) and played violin on the classic U2 song "Sunday Bloody Sunday", as well as recordings by Elvis Costello, the Hothouse Flowers, Sinéad O'Connor, and World Party.

[2][failed verification] Wickham is also accomplished with the mandolin, tin whistle, concertina, saxophone, piano, guitar and bones.

In 1990, Wickham, preferring an acoustic sound over rock, disagreed with Scott and Anthony Thistlethwaite over the direction of The Waterboys,[6] and left the band.

Wickham has experimented with a technique he calls "fuzz fiddle", partially inspired by rock fiddler Warren Ellis and the genre of grunge music.

", a cover of Bruce Springsteen's "Independence Day" and, in a nod to Jimi Hendrix's version of "The Star-Spangled Banner", has also used it in a performance of "Amhrán na bhFiann".