I would prefer those over hornpipes, aires, sets, etc. Karen Ashbrook is a good teacher and the House of Musical traditions in washington d.c. I love Al's work, too. Great to relax in front of the fire with a glass of wine and someone special beside you. Did Michael Flatley's success with Riverdance, etc. help to increase the listening and buying audience of celtic music.
Celtic music is very popular now.
The Celts have their own kind of religious tradition which i have read about regarding Pagan and the Druids. I would suggestany history of the Celts talks about it. Many people feel a spiritual connection to the music because of the ancient Gaelic songs and melodies are very beautiful and evoke maybe higher feelings. The hammered dulcimer originated in ancient Persia and is still considered the classical instrument of Iran today with very intricate system of music notation ornamentations and scales and tuning. I have studied the Santur, as it is called in Iran and loved the sounds, it is very demanding techniques and a real challenge for any modern players today.