"As someone described it - the music was coming up from the manholes. They had over 8,000 people singing a mass rendition of "Danny Boy" in Guildhall Square at 12.30 - one of them was me. It started at Grianan an Eileach at 5 in the morning, later a hot Air Balloon orchestra flying over the city, and the music making lasted 24 hours, with music of all kinds taking place at every street corner, church, square etc. Finishing with a rock/pop concert in Ebrington Square that night - though I didn't stay for that."
Here is the only video found so far of that stirring event.
http://www.londonderrysentinel.co.uk/lifestyle/entertainment/local-scene/thousands-participate-in-danny-boy-record-attempt-1-5213948