Sometimes, while I'm driving, I'll spontaneously start singing show tunes
Show tunes are popular songs originally written as part of a score of show.  Very singable.
Usually once I start singing, whoever I'm driving with will start singing too
, and George Gershwin came from their shows. (Even into the television and rock era, a few stage musicals managed to turn their show tunes into major pop music hits, sometimes aided by film adaptations and exposure through variety shows.) Although show tunes no longer have such a major role in popular music as they did in their heyday, they remain somewhat popular, especially among niche audiences. Show tunes make up a disproportionate part of the songs in most variations of the Great American Songbook.
The reverse phenomenon,
and Clare and released on three CDs in the 'Foinn Seisiun' series. Comhaltas has also published the musical notation for the tunes in three volumes.
After one set ends, someone will usually start another. A 'regular' at the session may launch into a set, knowing that many or all of the musicians know the tunes; a visitor starting a set will check that at least some of the other musicians know the tunes. While there may be occasional singing at a session, solo playing is not part