Based on doing at least 1,000 wedding receptions as a bandleader, my opinion is that the first dance should only be as long as the photographer needs to get a couple of good shots. Then the crowd stays on its high while the band launches into its next song as most of the wedding party and guests storm the dance floor...we have broken the ice and now we have the beginnings of a good party!
When I first began in this business, it seemed that every couple had "their song," but very few couples do now. So it is part of the bandleader's job to suggest one. But what does the bandleader do when a couple has very different musical tastes? By listening to what both of them say and looking for other clues as to what makes each "tick," we can find something that works for both. For instance, a recent groom wanted a Sinatraesque standard, while I sensed that his very fashion forward fiancée wanted something more contemporary. I asked her if a song from a recent movie soundtrack would work? We settled on "Night & Day" done as the Temptations did it in the movie, "What Women Want."
Another way of figuring out what to suggest when they have different tastes is to use the "Pandora approach." Pandora is a musical streaming service that suggests songs based on an analysis of the musical properties of the music that you tell them you like. A recent groom wanted an Elvis song for his first dance while his fiancée wanted something with a contemporary or reggae feel -- the solution was "Can't Help Falling in Love with You," one of Elvis' biggest hits but as recorded by the Stylistics.
Another couple told me they were interested in a standard with a country feel but the ultra hip bride told me privately that she really wanted electronic music. Using the Pandora approach I came up with the Pet Shop Boys eighties remake of "Always on my Mind," a classic Willie Nelson song.
There are certain songs that almost always work and some that do not work. "What a Wonderful World" is a top choice, I think, because it's Louis Armstrong's most identifiable hit (do you know anybody who doesn't like Louis?), has a simple but compelling lyric and was featured in the movie "Good Morning, Vietnam." "At Last" is also very popular for couples who dated for a long time or are a little older. "Just the Way You Are" has been around for a while but is still fresh (and almost everybody loves Billy Joel). Van Morrison's, "Someone Like You" is my own personal favorite for the same reasons as the Billy Joel song above.
A bandleader must also give his honest opinion when he thinks the bride and groom are considering a song that will not work. Over the years "Go Away Little Girl," "50 Different Ways To Leave Your Lover," "What's Love Got To Do With It," "Achy Breaky Heart," "Like a Virgin," "It's Rainin' Men" and "If You Wanna Be Happy For the Rest of Your Life (Make an Ugly Woman Your Wife)," have all been discussed as first songs and, thank God, rejected.