Why sing harmony?
Why sing?
For me the answer to each contains much the same elements; "because I can", "because it feels good", "because it seems to create good results", "because others like it" are all parts of the answers. Almost all of the posts above have said the relevant bits better than I but there are some experiences I have been reminded of by a few of the posts.

Some songs, for me, cry out for multiple voices. They might sound terrific sung solo and might sound terrific, but different, if accompanied by instruments. A small group may sing them with transcendental effect and a massed choir have a similarly transforming effect but by different means. I've been fortunate to have experienced all of these, in a wide variety of settings. Sorry for the pun.

Most of the people who've posted here seem to share lots of experience and bring that experience to bear in their comments but every now and then you realise you're in the company of newcomers or people who have a different view of the things you've taken for granted. Sometimes this opens your eyes and sometimes you just want to close your ears. Learning to take the bad with the good is an ongoing process although I confess to trying to encourage beginners with (hopefully) helpful advice.

The ones that are difficult are those people who don't seem to 'hear' the way we'd like them to. Like the 'hippies' (for want of a better term) for whom structure seemed to be anathema and, whenever you started on a song or a tune, regarded this as an invitation to improvise harmonies. Sigh! Often such people would turn up at a woolshed (or "bush") dance where the evening would be full of traditional dances (couples, long sets, quadrilles, circles etc) and they'd want to do their free-form imitations of Isidora Duncan. As an MC I could usually be successful in getting them to keep such efforts to the back of the hall and out of the way of the sets. Singing sessions (and tune sessions) required more diplomacy.

Over the years some of the 'hippies' picked up the skills of dealing with structure and turned their improvisation skills to good use with great harmony but I'm not sure they were aware of the forbearance that was required. I'm certainly not going to remind them. I'm just pleased they're keeping the harmonies going.