The significance is that this is the FIRST time I have received a booking from someone after seeing a performance (Mrs Pavane gets this all the time)

PS
Danny Boy is English, of course, although the tune may have been derived from a Scottish original before being collected in Ireland.

Galway Bay is not folk song, being attributed to Arthur Colahan (or is it Colohan - sources vary). But the words recorded by Bing Crosby were not quite the original version.
See, for example Tain 16