I understand that the parade for St. Patrick's Day (March 17) is really BIG in NYC and something that both locals and tourists look forward to as it's an important tradition in town every year.
The streets were indeed crowded even though the weather wasn't great; people of all ages were eager to see the parade so they were standing there since early in the morning. However, even though it was crowded and I arrived there by noon, I managed to find a not-so-bad spot to look at the parade from -- mind you, it wasn't a very central location either as I was around the 83-84th street, so pretty far up north on Central Park's east side. Fortunately the route of the parade was pretty long... It was fun and something I had never seen before anywhere, so a nice first-time experience too.
There were many bands of bagpipers that paraded one after the other but most of them were pretty good and you couldn't tell the difference among them, except perhaps in their outfit.... I like this kind of music very much but after a while it does get a bit monotonous...
These bands were somewhat noisy and I listened to them for a long while, but it was fun to see so many bagpipers in the same place at the same time with those colorful and pretty costumes!
This is a big parade, down the fifth avenue, to celebrate Ireland's great day... actually, today, many of the people on the parade are not Irish, but still a great parade, anyway, isn't it? :-)
Many of the groups are policemen, firemen, war veterans, soldiers... where many Irish people worked, but also several civil societies show up on this long line, smiling, greeting and partying the way on.
On the 17th of March there is a parade in honour of the Irish as St Patrick is its patron. You should wear something in green