is that a roddy doyle book????
well, to answer your question, it doesnt represent Irish contemporary R & B because all the songs are covers of earlier 'american' R & B..... for example
mustang sally (Blues song written and first recorded by Mack Rice in 1965)
take me to the river (Al Green, from the 70's)
try a little tenderness (bing crosby, in 1933)
i cant stand the rain (anna pebbles, 1974)
Do Right Woman Do Right Man (aretha franklin, 1964)
In The Midnight Hour (wilson pickett, 1965)
Bye Bye Baby (4 seasons from 1953, made famous by Bay city rollers 1975)
but i would argue that the theme of the movie represents, fairly accurately, Dublin society of the time....