Almost everyone knows the Wild Rover and the Leaving of Liverpool. recently, after the success of 'Brother where art Thou' 'Down to the River to Pray' is much heard. Two 'Little boys is' still popular and well known. 'I know an old lady who swallowed a fly' is a good joiner-inner.' You know that was the last thing on my mind' or 'Yellow is the colour of my true loves hair' are popular near contemporary tunes.Almost anything by Lonnie Donnegan. 'A rovin' and 'what shall we do with a drunken sailor for sea songs', though many shanties have very easy choruses.
I find that when the crowd are warmed up and enjoying it, I can do anything woth a reasonably easy chorus and they'll have a go.