The rising of the sun
And the running of the deer,
The playing of the merry organ,
Sweet singing in the choir.
"Merry" is not usually the word I'd associate with a pipe organ. One site claimed that the word meant "great," which would certainly fit, but volume 1 of the OED and a jeweler's loupe found nothing resembling that, so the usual "happy" meanings apply. ("Merry-bout" meant what you probably think it did.)
So was the organ a merry accordion, perhaps? Or a jazz organist on the church organ? The song is older than 1700, but there were plenty of church organs then. Were church songs upbeat, as a rule?
Along the way, I stumbled on this from Wikipedia: "Henry VIII wrote a love song Green groweth the holly which alludes to holly and ivy resisting winter blasts and not changing their green hue So I am and ever hath been Unto my lady true."