The reason I asked about the theme tune was because when Dallas was at its height in the early 80s I was teaching in a middle school. i was frequently called upon to play the piano for assembly in the absence of the music teacher (who had only one tune in her repertoire). One day I played the children out to the Dallas theme. At break time I was summoned to see the deputy headmistress who told me that I should not be so frivolous in future; I had nearly single-handedly destroyed the discipline of the school because the children, instead of filing out in silence had marched along the corridors singing the theme to "la". Needless to say the rest of the staff, including the Headmaster, were more appreciative.