There are literally hundreds of Irish sessions held daily all around the world, and as in Ireland, each session tends to have their own collection of tunes shared by the group, any which may be “universal” and some quite local and unknown in other sessions. The goal is to have a body of tunes shared by most participants, large enough to avoid playing the same tunes every week, but with enough shared tunes so no one is left out of the fun.  Often, an advanced player will introduce a new tune to the group by including it in a set of two other well known tunes. Click here for a current list of popular tunes played at the Tucson Session Another critical aspect of playing tunes is The Set. Tunes are usually grouped in sets of 3 and often the transitions from tune to tune are as important as the tunes themselves. The transition from a major key to a minor and then a major can  add great excitement to the music. The same with unexpected key changes or “completing a set” using a minor key. Listening to and understanding the sets arranged by some of the great players can be extremely illuminating.
The Jim Coogan SessionTune Book
The Bob Denton Irish Banjo Tab Book
The O'Flaherty 100 Irish Tunes
The O'Flaherty 100 More Irish Tunes
Blarney Stone Pub Irish Session Tunes Book 1
Blarney Stone Pub Irish Session Tunes Book 2