This is a movie about those things that happens in life, during a summer brake, a travel, a short moment of time when you meet someone and something special happens. Something that lasts only for a brief moment of time but still lasts forever; hence the title: Once.
In addition to that there is a strong musical element in it, not as forward as in The Commitments but probably even more beautiful. The actors are not actors but musicians but this somehow makes it all more belivable.
Enjoyable to say at least, and one to make us all remember what “once” happened.