Find 10 Daniel O'Donell songs..you'll have 5 mins to spare at the end of the half hour, and no-one will remember what you played.!
On a more serious note, 'Down By The Sally Gardens'or the done to death 'Fields of Athenry'. Which still gets a great round of applause here in the UK's irish pubs and clubs. Something by Christy Moore, perhaps. Some of Mary Blacks earlier, more folky stuff. A Paul Brady song. Something horrendous by Brendan Shine (for comedy). An acoustic version of a U2 song. Just some ideas.